Server unexpectedly closed network connection

I have a client using WinSCP Ver. 3.8.2 (Build 330) for the last 6 months without issue. Now when she attempts to connect to host server the gets the error posted within the subject line.
the network environment has not changed. We have 1.5 DSL with a Cisco PIX firewall both before and after the problem started.
Here is a copy of the logfile.
. 2007-10-05 14:36:24.689 --------------------------------------------------------------------------
. 2007-10-05 14:36:24.689 WinSCP Version 3.8.2 (Build 330) (OS 5.1.2600 Service Pack 2)
. 2007-10-05 14:36:24.689 Login time: Friday, October 05, 2007 2:36:24 PM
. 2007-10-05 14:36:24.689 --------------------------------------------------------------------------
. 2007-10-05 14:36:24.689 Session name: jerry
. 2007-10-05 14:36:24.689 Host name: sftp.XX.XXX (Port: 22)
. 2007-10-05 14:36:24.689 User name: XXX-XX-XXXXXX\name (Password: No, Key file: No)
. 2007-10-05 14:36:24.689 Transfer Protocol: SFTP (SCP)
. 2007-10-05 14:36:24.689 SSH protocol version: 2; Compression: No
. 2007-10-05 14:36:24.689 Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
. 2007-10-05 14:36:24.689 Ciphers: aes,blowfish,3des,WARN,des; Ssh2DES: No
. 2007-10-05 14:36:24.689 Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
. 2007-10-05 14:36:24.689 SSH Bugs: -,-,-,-,-,-,-,-
. 2007-10-05 14:36:24.689 SFTP Bugs: -,-,-
. 2007-10-05 14:36:24.689 Proxy: none
. 2007-10-05 14:36:24.689 Return code variable: Autodetect; Lookup user groups: Yes
. 2007-10-05 14:36:24.689 Shell: default, EOL: 0
. 2007-10-05 14:36:24.689 Local directory: default, Remote directory: home, Update: No, Cache: Yes
. 2007-10-05 14:36:24.689 Cache directory changes: Yes, Permanent: Yes
. 2007-10-05 14:36:24.689 Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
. 2007-10-05 14:36:24.689 Alias LS: No, Ign LS warn: Yes, Scp1 Comp: No
. 2007-10-05 14:36:24.689 --------------------------------------------------------------------------
. 2007-10-05 14:36:24.689 Looking up host "sftp.XX.XXX"
. 2007-10-05 14:36:24.689 Connecting to XX.XXX.XX.XXX port 22
. 2007-10-05 14:36:24.814 Server unexpectedly closed network connection
* 2007-10-05 14:36:24.814 (ESshFatal) Server unexpectedly closed network connection

Thank you,
Jer

She should first check in local firewall on her workstation does not block a WinSCP connection. Second you should verify whether the connection attempt has ever reached your server and if it does why the server refused it.