ftp issues

We have an FTP server, W2K SP4. We have a remote client that has an assigned directory on the server to which they upload a file.

They tried uploading today and were able to access their home directory but not view or upload anything.

They received an error ‘unkown socket error’ from their ftp client program.. voyager ftp

The only changes to our network were not on the firewall. Network settings have not been changed either.

I have been installing Microsoft Updates and patches for all of our servers.

Could these updates or patches affect ftp? What else could I check?