Could not retrieve directory listing

Hi,we have been using winscp successfuly for files transfer.
Recently connections just dropped with error 'Could not retrieve directory listing'. Below is relevant logs. Appreciate help.
Thanks.

. 2010-07-29 10:50:20.600 --------------------------------------------------------------------------
. 2010-07-29 10:50:20.600 WinSCP Version 4.2.7 (Build 758) (OS 5.2.3790 Service Pack 2)
. 2010-07-29 10:50:20.600 Login time: Thursday, July 29, 2010 10:50:20 AM
. 2010-07-29 10:50:20.600 --------------------------------------------------------------------------
. 2010-07-29 10:50:20.600 Session name: user@company.com
. 2010-07-29 10:50:20.600 Host name: company.com (Port: 21)
. 2010-07-29 10:50:20.600 User name: user (Password: Yes, Key file: No)
. 2010-07-29 10:50:20.600 Tunnel: No
. 2010-07-29 10:50:20.600 Transfer Protocol: FTP
. 2010-07-29 10:50:20.600 Ping type: C, Ping interval: 30 sec; Timeout: 15 sec
. 2010-07-29 10:50:20.600 Proxy: none
. 2010-07-29 10:50:20.600 FTP: FTPS: None; Passive: Yes [Force IP: No]
. 2010-07-29 10:50:20.600 Local directory: default, Remote directory: home, Update: No, Cache: Yes
. 2010-07-29 10:50:20.600 Cache directory changes: Yes, Permanent: Yes
. 2010-07-29 10:50:20.600 DST mode: 1
. 2010-07-29 10:50:20.600 --------------------------------------------------------------------------
. 2010-07-29 10:50:20.600 Connecting to company.com ...
. 2010-07-29 10:50:21.865 Connected with company.com. Waiting for welcome message...
< 2010-07-29 10:50:22.396 220 company.com FTP server (SecureTransport 4.9.1) ready.
> 2010-07-29 10:50:22.396 USER user
< 2010-07-29 10:50:22.912 331 Password required for user
> 2010-07-29 10:50:22.912 PASS **********
< 2010-07-29 10:50:23.959 230 Virtual user userlogged in.
> 2010-07-29 10:50:23.959 SYST
< 2010-07-29 10:50:24.490 215 UNIX Type: L8
> 2010-07-29 10:50:24.490 FEAT
< 2010-07-29 10:50:25.006 211-Extensions supported
< 2010-07-29 10:50:25.006 AUTH
< 2010-07-29 10:50:25.006 USER
< 2010-07-29 10:50:25.006 PASS
< 2010-07-29 10:50:25.006 QUIT
< 2010-07-29 10:50:25.006 PORT
< 2010-07-29 10:50:25.006 PASV
< 2010-07-29 10:50:25.006 EPSV
< 2010-07-29 10:50:25.006 TYPE
< 2010-07-29 10:50:25.006 STRU
< 2010-07-29 10:50:25.006 MODE
< 2010-07-29 10:50:25.006 RETR
< 2010-07-29 10:50:25.006 STOR
< 2010-07-29 10:50:25.006 ABOR
< 2010-07-29 10:50:25.006 DELE
< 2010-07-29 10:50:25.006 CWD
< 2010-07-29 10:50:25.006 XCWD
< 2010-07-29 10:50:25.006 LIST
< 2010-07-29 10:50:25.006 NLST
< 2010-07-29 10:50:25.006 SITE
< 2010-07-29 10:50:25.006 SYST
< 2010-07-29 10:50:25.006 STAT
< 2010-07-29 10:50:25.006 HELP
< 2010-07-29 10:50:25.006 NOOP
< 2010-07-29 10:50:25.006 MKD
< 2010-07-29 10:50:25.006 XMKD
< 2010-07-29 10:50:25.006 RMD
< 2010-07-29 10:50:25.006 XRMD
< 2010-07-29 10:50:25.006 PWD
< 2010-07-29 10:50:25.006 XPWD
< 2010-07-29 10:50:25.006 CDUP
< 2010-07-29 10:50:25.006 XCUP
< 2010-07-29 10:50:25.006 SIZE
< 2010-07-29 10:50:25.006 MDTM
< 2010-07-29 10:50:25.006 RNFR
< 2010-07-29 10:50:25.006 RNTO
< 2010-07-29 10:50:25.006 REST
< 2010-07-29 10:50:25.006 FEAT
< 2010-07-29 10:50:25.006 ADAT
< 2010-07-29 10:50:25.006 PROT
< 2010-07-29 10:50:25.006 PBSZ
< 2010-07-29 10:50:25.006 APPE
< 2010-07-29 10:50:25.006 XCRC
< 2010-07-29 10:50:25.006 CCC
< 2010-07-29 10:50:25.006 COMB
< 2010-07-29 10:50:25.006 UTF8
< 2010-07-29 10:50:25.647 211 END
> 2010-07-29 10:50:25.647 OPTS UTF8 ON
< 2010-07-29 10:50:26.162 500 'OPTS UTF8 ON': command not understood.
. 2010-07-29 10:50:26.162 Connected
. 2010-07-29 10:50:26.162 Got reply 1 to the command 1
. 2010-07-29 10:50:26.162 --------------------------------------------------------------------------
. 2010-07-29 10:50:26.162 Using FTP protocol.
. 2010-07-29 10:50:26.162 Doing startup conversation with host.
> 2010-07-29 10:50:26.162 PWD
< 2010-07-29 10:50:26.678 257 "/" is current directory.
. 2010-07-29 10:50:26.678 Got reply 1 to the command 16
. 2010-07-29 10:50:26.678 Getting current directory name.
. 2010-07-29 10:50:26.678 Startup conversation with host finished.
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Copying 0 files/directories to remote directory "/loreal04-my-ftp-prod/CMD/outbox/"
. 2010-07-29 10:50:26.678 PrTime: Yes; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 01; Resume: S (102400); CalcS: No; Mask:
. 2010-07-29 10:50:26.678 TM: M; ClAr: No; CPS: 0; ExclM(No):
. 2010-07-29 10:50:26.678 AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Copying 0 files/directories to remote directory "/loreal04-my-ftp-prod/DELIVERIES/outbox/"
. 2010-07-29 10:50:26.678 PrTime: Yes; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 01; Resume: S (102400); CalcS: No; Mask:
. 2010-07-29 10:50:26.678 TM: M; ClAr: No; CPS: 0; ExclM(No):
. 2010-07-29 10:50:26.678 AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2010-07-29 10:50:26.678 Session upkeep
. 2010-07-29 10:50:26.678 Copying 1 files/directories to remote directory "/loreal04-my-ftp-prod/INBOUND/outbox/"
. 2010-07-29 10:50:26.678 PrTime: Yes; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 01; Resume: S (102400); CalcS: No; Mask:
. 2010-07-29 10:50:26.678 TM: M; ClAr: No; CPS: 0; ExclM(No):
. 2010-07-29 10:50:26.678 AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2010-07-29 10:50:26.678 File: "D:\WORK\CO\INBOUND\file72901.TXT"
. 2010-07-29 10:50:26.678 Copying "D:\WORK\CO\INBOUND\file72901.TXT" to remote directory started.
. 2010-07-29 10:50:26.678 Ascii transfer mode selected.
. 2010-07-29 10:50:26.678 Starting upload of D:\WORK\MY\IDS.OUTBOX\INBOUND\MYGRIDS10072901.TXT
> 2010-07-29 10:50:26.678 CWD /lcompany-pr/INBOUND/outbox/
< 2010-07-29 10:50:27.209 250 CWD command successful.
> 2010-07-29 10:50:27.209 PWD
< 2010-07-29 10:50:27.725 257 "/lcompany-pr/INBOUND/outbox" is current directory.
> 2010-07-29 10:50:27.725 TYPE A
< 2010-07-29 10:50:28.256 200 Type set to A.
> 2010-07-29 10:50:28.256 PASV
< 2010-07-29 10:50:28.772 227 Entering Passive Mode (202,67,157,110,19,136)
> 2010-07-29 10:50:28.772 LIST
. 2010-07-29 10:50:29.787 total 0
< 2010-07-29 10:50:29.803 150 Opening ASCII mode data connection for file list.
< 2010-07-29 10:50:30.459 226 Transfer complete.
> 2010-07-29 10:50:30.459 TYPE A
< 2010-07-29 10:50:30.975 200 Type set to A.
> 2010-07-29 10:50:30.975 PASV
< 2010-07-29 10:50:31.490 425 Can't open passive connection: Cannot assign requested address.
> 2010-07-29 10:50:31.490 PORT 192,6,171,40,11,134
< 2010-07-29 10:50:32.053 500 Illegal PORT Command.
. 2010-07-29 10:50:32.053 Copying files to remote side failed.
. 2010-07-29 10:50:32.053 Got reply 4 to the command 4
* 2010-07-29 10:50:32.053 (ExtException) total 0
* 2010-07-29 10:50:32.053 Copying files to remote side failed.
* 2010-07-29 10:50:32.053 Illegal PORT Command.
. 2010-07-29 10:50:32.053 Asking user:
. 2010-07-29 10:50:32.053 Error transferring file 'D:\WORK\CO\INBOUND\file72901.TXT'. ("total 0","Copying files to remote side failed.","Illegal PORT Command.")
* 2010-07-29 10:50:32.053 (EScpSkipFile) Error transferring file 'D:\WORK\CO\INBOUND\file72901.TXT'.
* 2010-07-29 10:50:32.053 total 0
* 2010-07-29 10:50:32.053 Copying files to remote side failed.
* 2010-07-29 10:50:32.053 Illegal PORT Command.
. 2010-07-29 10:50:32.053 Session upkeep
. 2010-07-29 10:50:32.053 Got reply 1004 to the command 4
. 2010-07-29 10:50:32.053 Disconnected from server

more info:

At times the error is:
'could not retrieve directory listing'
'Can't open passive connection'
'Cannot assign requested address'

This is strange as the program has been working fine for the past few months. All of a sudden, these error.
Help!!!!

Can you connect with any other FTP client?

Hi Martin,

Thank you for the response.
Issue resolved. We managed to find the root cause of the intermittent ftps connection, due to saturated bandwith at one of the receipient end.

Thanks again.

regards