Hangs very often on FTP connection

WinSCP hangs very ofter during FTP session.

Also, there are many timouts/random disconnections when connected to FTP servers. I have tried to set keepalive to 10 secs, but without any result.

WinSCP version: 4.1.7. (build 413)
OS: Vista Ultimate

Protocol: FTP
Interface: Commander

Please post a log file.