Connection Problem

I've been using smart ftp for awhile now and I could always connect just fine. Recently though I've been getting an error message while trying to do so. I am hosted on a friend's server with a few other people and they have all been able to connect just fine, but I keep getting this message: No connection could be made because the target machine actively refused it. Connection closed.

I turned off my firewall and virus protection and still no luck. Any ideas on what to do?