Hmmm...Have you tried going to the Windows Update or Microsoft Download page and getting the latest USB Mass Storage Device drivers there?
If that doesn't solve it, it could be a hardware issue. Especially considering that there seems to be a conflict between the two devices, I get the feeling that's probably your real issue.
-The MinisterofDOOM 
|The Q of DOOM| - |The Maxima| - | Hear my Q!|
4.08 VLSD, NICO 8-way ECU, full exhaust with custom headers,
Tokico Blues with Eibach springs, Stillen FSTB, 20mm RSB, 255 rear rubber.