Also, I forgot to mention that I CAN use the thumb button if I am mousing around on my secondary (Vista) machine to toggle back to primary (XP) but not the other way around. Thanks!
So I just purchased Pro and I am running 1.05 on both machines. My primary machine is XP SP2, my secondary machine is running Vista RC1. I use Multiplicity in locked desktop mode and then use my thumb button to switch machines, however after I started using 1.05 I havent been able to switch using Thumb button. Any ideas? Also, I think a nice feature would be if you hold shift and then hit thumb button, you could switch to a third machine.