Have you tried to FTP from the Run command? If not, try that first to eliminate FTP Commander as the cause.
Click Start, Run, then type in your FTP in this manner with double ftp and space between:
ftp click here
and click OK. Then enter you email ID, press Enter, then insert your password and press Enter again. You should get a report on the space status of your site, confirming that you're connected to it.