This is not a fix for the problem, but a workaround. It appears that if you open the CLSID for Printers, the redirected printers are displayed.
Execute the following from the Start menu, or Start->Run dialog
explorer shell:::{863aa9fd-42df-457b-8e4d-0de1b8015c60}
or
explorer shell:::{2227A280-3AEA-1069-A2DE-08002B30309D}