Not having any luck with a Bamboo and a Graphire for simultaneous control via the wacom object (computer freezes, can't force quit max). Perhaps missing something about the device ID arguments... This is on a MBP 2.4, OS 10.5.4, driver version 5.0.5-3.
Tried Max 4.6 and 5, tried the newer wacom driver as well.
If anyone has got this to work I'd be interested to know how. If it's not possible I'll set up a mac mini to host the second tablet via osc.