>Any ideas?

It's probably just because that old VFP code doesn't support new protocol of the FTP at the other end. I would look for that. In our case, it happened recently that a FTP server was using the SFTP protocol. I bumped into that and starting to find a way around. The problem is that this is not natively supported in the .NET Framework. So, there was no way to support communication with that server as is.