Problem Transferring 4.3 GB file

I am trying to transfer a large file using ftp, but it always fails. The transfer goes well for several hours (indicating an estimated completion time of 4-7 hours) but it never completes. Attached is a screen shot after ~12 hours. I also tried drag and drop; same outcome.

Version: 4.3.9
OS: Windows7 64 bit
Protocol: ftp
Using GUI with Commander Interface (I believe)
Log: see below

Any suggestions would be appreciated.

Thank you

LOG FILE:
--------------------------------------------------------------------------
WinSCP Version 4.3.9 (Build 1817) (OS 6.1.7601 Service Pack 1)
Configuration: HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\
Local account: toro-Laptop\toro
Login time: Friday, August 03, 2012 7:53:35 PM
--------------------------------------------------------------------------
Session name: interoil ftp (Modified stored session)
Host name: ftp.interoil.ch (Port: 21)
User name: ds04 (Password: Yes, Key file: No)
Tunnel: No
Transfer Protocol: FTP
Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
Proxy: none
FTP: FTPS: None; Passive: Yes [Force IP: A]
Local directory: default, Remote directory: home, Update: No, Cache: Yes
Cache directory changes: Yes, Permanent: Yes
DST mode: 1
--------------------------------------------------------------------------
Connecting to ftp.interoil.ch ...
Connected with ftp.interoil.ch. Waiting for welcome message...
220 Microsoft FTP Service
USER ds04
331 Password required for ds04.
PASS **********
230 User ds04 logged in.
SYST
215 Windows_NT
FEAT
211-FEAT
SIZE
MDTM
211 END
Connected
--------------------------------------------------------------------------
Using FTP protocol.
Doing startup conversation with host.
PWD
257 "/" is current directory.
Getting current directory name.
Retrieving directory listing...
TYPE A
200 Type set to A.
PASV
227 Entering Passive Mode (212,203,120,187,7,4).
LIST -a
125 Data connection already open; Transfer starting.
226 Transfer complete.
Directory listing successful
Startup conversation with host finished.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Connected with ftp.interoil.ch. Waiting for welcome message...
[Background 1] 220 Microsoft FTP Service
[Background 1] USER ds04
[Background 1] 331 Password required for ds04.
[Background 1] PASS **********
[Background 1] 230 User ds04 logged in.
[Background 1] SYST
[Background 1] 215 Windows_NT
[Background 1] FEAT
[Background 1] 211-FEAT
[Background 1] SIZE
[Background 1] MDTM
[Background 1] 211 END
[Background 1] Connected
[Background 1] --------------------------------------------------------------------------
[Background 1] Using FTP protocol.
[Background 1] Doing startup conversation with host.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Changing directory to "/".
[Background 1] CWD /
[Background 1] 250 CWD command successful.
[Background 1] Getting current directory name.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Retrieving directory listing...
[Background 1] TYPE A
[Background 1] 200 Type set to A.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,7,14).
[Background 1] LIST -a
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] 226 Transfer complete.
[Background 1] Directory listing successful
[Background 1] Startup conversation with host finished.
[Background 1] File: "/be_CA_d_09.120712083728.chws024.tgz"
[Background 1] Copying "/be_CA_d_09.120712083728.chws024.tgz" to local directory started.
[Background 1] Binary transfer mode selected.
[Background 1] Starting download of /be_CA_d_09.120712083728.chws024.tgz
[Background 1] TYPE I
[Background 1] 200 Type set to I.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,7,15).
[Background 1] RETR be_CA_d_09.120712083728.chws024.tgz
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] Timeout detected.
[Background 1] Copying files from remote side failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Timeout detected.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Timeout detected.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Timeout detected.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Timeout detected.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Timeout detected.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] No connection could be made because the target machine actively refused it.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
[Background 1] Connection failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Connected with ftp.interoil.ch. Waiting for welcome message...
[Background 1] 220 Microsoft FTP Service
[Background 1] USER ds04
[Background 1] 331 Password required for ds04.
[Background 1] PASS **********
[Background 1] 230 User ds04 logged in.
[Background 1] SYST
[Background 1] 215 Windows_NT
[Background 1] FEAT
[Background 1] 211-FEAT
[Background 1] SIZE
[Background 1] MDTM
[Background 1] 211 END
[Background 1] Connected
[Background 1] Doing startup conversation with host.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Changing directory to "/".
[Background 1] CWD /
[Background 1] 250 CWD command successful.
[Background 1] Getting current directory name.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Startup conversation with host finished.
[Background 1] File: "/be_CA_d_09.120712083728.chws024.tgz"
[Background 1] Copying "/be_CA_d_09.120712083728.chws024.tgz" to local directory started.
[Background 1] Binary transfer mode selected.
[Background 1] Starting download of /be_CA_d_09.120712083728.chws024.tgz
[Background 1] TYPE A
[Background 1] 200 Type set to A.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,4,8).
[Background 1] LIST -a
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] 226 Transfer complete.
[Background 1] TYPE I
[Background 1] 200 Type set to I.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,4,10).
[Background 1] REST 945187368
[Background 1] 350 Restarting at 945187368.
[Background 1] RETR be_CA_d_09.120712083728.chws024.tgz
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] Timeout detected.
[Background 1] Copying files from remote side failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Connected with ftp.interoil.ch. Waiting for welcome message...
[Background 1] 220 Microsoft FTP Service
[Background 1] USER ds04
[Background 1] 331 Password required for ds04.
[Background 1] PASS **********
[Background 1] 230 User ds04 logged in.
[Background 1] SYST
[Background 1] 215 Windows_NT
[Background 1] FEAT
[Background 1] 211-FEAT
[Background 1] SIZE
[Background 1] MDTM
[Background 1] 211 END
[Background 1] Connected
[Background 1] Doing startup conversation with host.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Changing directory to "/".
[Background 1] CWD /
[Background 1] 250 CWD command successful.
[Background 1] Getting current directory name.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Startup conversation with host finished.
[Background 1] File: "/be_CA_d_09.120712083728.chws024.tgz"
[Background 1] Copying "/be_CA_d_09.120712083728.chws024.tgz" to local directory started.
[Background 1] Binary transfer mode selected.
[Background 1] Starting download of /be_CA_d_09.120712083728.chws024.tgz
[Background 1] TYPE A
[Background 1] 200 Type set to A.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,11,153).
[Background 1] LIST -a
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] 226 Transfer complete.
[Background 1] TYPE I
[Background 1] 200 Type set to I.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,11,155).
[Background 1] REST 4490750503
[Background 1] 501 Reply marker is invalid.
[Background 1] Resume command not supported by server, overwriting file.
[Background 1] RETR be_CA_d_09.120712083728.chws024.tgz
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] Timeout detected.
[Background 1] Copying files from remote side failed.
[Background 1] Connecting to ftp.interoil.ch ...
[Background 1] Connected with ftp.interoil.ch. Waiting for welcome message...
[Background 1] 220 Microsoft FTP Service
[Background 1] USER ds04
[Background 1] 331 Password required for ds04.
[Background 1] PASS **********
[Background 1] 230 User ds04 logged in.
[Background 1] SYST
[Background 1] 215 Windows_NT
[Background 1] FEAT
[Background 1] 211-FEAT
[Background 1] SIZE
[Background 1] MDTM
[Background 1] 211 END
[Background 1] Connected
[Background 1] Doing startup conversation with host.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Changing directory to "/".
[Background 1] CWD /
[Background 1] 250 CWD command successful.
[Background 1] Getting current directory name.
[Background 1] PWD
[Background 1] 257 "/" is current directory.
[Background 1] Startup conversation with host finished.
[Background 1] File: "/be_CA_d_09.120712083728.chws024.tgz"
[Background 1] Copying "/be_CA_d_09.120712083728.chws024.tgz" to local directory started.
[Background 1] Binary transfer mode selected.
[Background 1] Starting download of /be_CA_d_09.120712083728.chws024.tgz
[Background 1] TYPE A
[Background 1] 200 Type set to A.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,19,93).
[Background 1] LIST -a
[Background 1] 125 Data connection already open; Transfer starting.
[Background 1] 226 Transfer complete.
[Background 1] TYPE I
[Background 1] 200 Type set to I.
[Background 1] PASV
[Background 1] 227 Entering Passive Mode (212,203,120,187,19,95).
[Background 1] REST 4490750503
[Background 1] 501 Reply marker is invalid.
[Background 1] Resume command not supported by server, overwriting file.
[Background 1] RETR be_CA_d_09.120712083728.chws024.tgz
[Background 1] 125 Data connection already open; Transfer starting.

Seems that the server has problems transferring files over 4 GiB.
First, not sure why the transfer times out. May be related.
After timeout, WinSCP reconnects and tried to resume the transfer. It works as long as the already transferred side is below 4 GiB. Once it is over the threshold, your server malfunctions and fails to resume the transfer. Hence the transfer restarts from the scratch.