Unable to change to root directory

I'm using SmartFTP 1.0.981.

I login to an FTP server (WFTPD 3.10.1) and the home directory displays fine.

Whenever I attempt to change to the root directory of a volume I receive the message

501 User is not allowed to change to /C: - returning to...

If I enter, from the command line or via the change folder dialog, the command CWD /C:/ or by clicking the root drive in the remote tree, the command I recieve the same message.

If I enter the from the command line or via the change folder dialog, the command CWD /C:// everything works fine.

I tried all the stuff in the "Bugs Report" stuff (re-install etc) with no luck. Suggestions anyone?