Remote Desktop Local Drives not showing c drive

[Davidi]

Hello,
A couple remote users are experiencing the following issue:

They have both checked the "Drives" checkbox in the Local Resources tab of
their Remote Desktop settings but when connecting, their local c: drive does
not show up. All other drives (ie. D drive) appear just fine. Their local
printers also appear without a problem when they check Printers from Local
Resources.

The remote computers are Windows XP SP2 and Windows Vista SP1.

We don't have a Group Policy set up to deny any access to Remote Desktop.
The setting used to work just fine. We did recently install some Windows XP
hotfixes.

Any ideas? Thanks!