Because cPanel has a character limit of 8 characters for user names, your cPanel & FTP user name may be slightly different from your member ID used to log into your member zone.
If your member ID is greater than 8 characters, your cPanel & FTP user name should be the first 8 characters of your member ID.
To verify your cPanel/FTP user name, simply click on the "FTP Info" link under the quick reference section of your member zone and your user name will be displayed under that link.