I to have experienced a similar problem before...

Winsockfix.exe helped me alot, it's a tool that replaces some registry keys and fixes your tcp/ip settings, which usually get messed up when using tools like spybot and adaware...

You can get it here: http://www.tacktech.com/display.cfm?ttid=257

Hoped this helped a little...

***EDIT***

Did not see dr. toker's post...

Either way this might help someone lol...