Are you able to FTP to the same server using any other FTP client?
I have no clue, I wouldn't know how to do that. I am not tech savy at all. How do you do that?
Launch any browser and enter ftp://www.YOURSITE.com/ . It will promt you for authentication.
Enter the FTP username and password. Verify whether it goes smooth.
Otherwise download any FTP client like, FileZilla and try to connect using it.
It's the User Name we are stuck for. Adobe can't help any more as they no longer support Contribute CS5