Connection Problems

I'm having problems connecting to any FTP server, I type in the details (Server, Username, Password), and once I press enter to connect, the entire app locks up.
My computer is pretty slow (733 mhz), so I disabled a few Windows services which I don't need to free up sources. Can someone list any services which SmartFTP requires to connect and I'll be sure that they're running.
Whats strange is I disabled all the services and was able to use SmartFTP a few times before I ran into any problems, so anyone know what could also possibly cause this problem?

Hi, what SmartFTP build are you ussing? on what OS? plz give us more details, with that i only can think on windows nt kernel based OSs.

SmartFTP build 1.0.982
Windows XP Pro SP2 with latest updates installed

I just uninstalled / reinstalled and it worked again, so I know the windows services weren't the problem.