Try this registry entry on the client PC:
In HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default\AddIns\RDPDR
Create a DWORD value named “FilterQueueType”. Its value should be “FFFFFFFF” (eight F’s), hexadecimal.
Works especially well for unusual printers, e.g., USB et cetera. Reportedly helps under XP, Vista, and 7.