Network error: Software caused connection abort

All,

Have a simple script that does a put of a few files.

It will work once, then not work. There are no variables, the script does not change, the destination directory is empty.

System is Windows 2003 R2 x64.
Version of WinSCP is 5.1.4

Any help would be appreciated!

Command:
"C:\Program Files (x86)\WinSCP\winscp" /ini=nul /script=c:\scripts\data.xfer /log=c:\logs\winscp.log

Source (data.xfer):
[code]
option confirm off
option batch abort
open sftp://username:password@172.XX.XX.XXX -hostkey="ssh-rsa 2048 aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa:aa"
cd /opt/monthend
put e:\monthend\tmp\*.sql
put e:\monthend\tmp\done.txt
exit
[/code]

Log File:
[code]
. 2013-04-26 12:20:07.327 --------------------------------------------------------------------------
. 2013-04-26 12:20:07.327 WinSCP Version 5.1.4 (Build 3020) (OS 5.2.3790 Service Pack 2)
. 2013-04-26 12:20:07.327 Configuration: nul
. 2013-04-26 12:20:07.327 Local account: administrator
. 2013-04-26 12:20:07.327 Working directory: C:\Dent-ECW\scripts
. 2013-04-26 12:20:07.327 Command-line: "C:\Program Files (x86)\WinSCP\WinSCP.exe" /console=514 /consoleinstance=_5756_508 "/ini=nul" "/script=c:\Dent-ECW\scripts\monthend.xfer" "/log=c:\Dent-ECW\logs\winscp.log"
. 2013-04-26 12:20:07.327 Time zone: Current: GMT-4, Standard: GMT-5, DST: GMT-4, DST Start: 3/10/2013, DST End: 11/3/2013
. 2013-04-26 12:20:07.327 Login time: Friday, April 26, 2013 12:20:07 PM
. 2013-04-26 12:20:07.327 --------------------------------------------------------------------------
. 2013-04-26 12:20:07.327 Session name: username@172.XX.XX.XXX (Ad-Hoc session)
. 2013-04-26 12:20:07.327 Host name: 172.XX.XX.XXX (Port: 22)
. 2013-04-26 12:20:07.327 User name: username (Password: Yes, Key file: No)
. 2013-04-26 12:20:07.327 Tunnel: No
. 2013-04-26 12:20:07.327 Transfer Protocol: SFTP
. 2013-04-26 12:20:07.327 Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
. 2013-04-26 12:20:07.327 Proxy: none
. 2013-04-26 12:20:07.327 SSH protocol version: 2; Compression: No
. 2013-04-26 12:20:07.327 Bypass authentication: No
. 2013-04-26 12:20:07.327 Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
. 2013-04-26 12:20:07.327 Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
. 2013-04-26 12:20:07.327 SSH Bugs: A,A,A,A,A,A,A,A,A,A
. 2013-04-26 12:20:07.327 SFTP Bugs: A,A
. 2013-04-26 12:20:07.327 Return code variable: Autodetect; Lookup user groups: A
. 2013-04-26 12:20:07.327 Shell: default
. 2013-04-26 12:20:07.327 EOL: 0, UTF: 2
. 2013-04-26 12:20:07.327 Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
. 2013-04-26 12:20:07.327 LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
. 2013-04-26 12:20:07.327 Local directory: default, Remote directory: home, Update: Yes, Cache: Yes
. 2013-04-26 12:20:07.327 Cache directory changes: Yes, Permanent: Yes
. 2013-04-26 12:20:07.327 DST mode: 1; Timezone offset: 0h 0m
. 2013-04-26 12:20:07.327 --------------------------------------------------------------------------
. 2013-04-26 12:20:07.327 Looking up host "172.XX.XX.XXX"
. 2013-04-26 12:20:07.327 Connecting to 172.XX.XX.XXX port 22
. 2013-04-26 12:20:07.342 Server version: SSH-2.0-OpenSSH_5.3
. 2013-04-26 12:20:07.342 Using SSH protocol version 2
. 2013-04-26 12:20:07.342 We claim version: SSH-2.0-WinSCP_release_5.1.4
. 2013-04-26 12:20:07.342 Network error: Software caused connection abort
[/code]