Hi Kent,
Just a quick note to let you know that I've reproduced the same problem here with a Wacom Graphire2 (ET-0405A-U) and Wacom driver 6.1.5-2 installed (the latest for that model of tablet)... I've filed an internal bug report to investigate and see if we can get this fixed. Thanks for letting us know about the problem and providing all the details!
Did you manage to configure the tablet to work with Fusion's USB passthrough?
Cheers,
--
Darius