Apologizes in advance if this question has already been answered.

I installed the trial version of contribute cs 4 (v5.0) in windows xp. Was
successfully able to connect to my website through sftp. Was able to
edit/discard changes made on there. Everything was going well.

Shutdown contribute. Restarted it.
Keeps telling me:

Contribute cannot connect to the server. Please check your connection
information or contact your administrator

Would anyone happen to encounter this problem before?

Did a lot of research through google and can't seem to find any answers.

Thanks in advance for your help!