FTP seems buggy

I have been using the FTP portion of DO for years and it has always been pretty good. However, recently it seems my uploads are amazingly slow and the time it takes to handshake with the server is forever. In addition, some files end up on the server with a zero byte size. My Web Host is GoDaddy and when I use their browser based FTP client, every thing works without a hitch. So when I call GoDaddy tech support, they always ask me what FTP client I am using and I tell them DO, and they've never heard of it and tell me to use the browser. Since the problem doesn't exist with the browser, their deductive reasoning tells them it must be DO. Could I get some feedback on this?

I can't think of anything which has changed recently and would cause that, so there's probably another factor causing the difference. That might be antivirus or firewall software/hardware, or changes on the server side.

Do you know if their upload tool uses the same type of connection? It may be using another protocol to the one you're using in Opus. (Opus may support the one they are using, depending on what it is.)

What does the FTP log say, and the other things in the FTP FAQ?