Setup Mac Pro 2.66 3 gig of Ram, Vista on an internal IDE drive. First bootup of vista, it uses it's own bluetooth drivers. Didn't catch what they were but my Mighty Mouse was working fine. Install Apple's system drivers, (includes apple bluetooth drivers) Mouse doesn't pair automatically now and I must use a USB mouse and make it work every reboot. Remove Bluetooth from device manager, restart. Vista no longer sees any bluetooth hardware. Interestingly enough, my first reboot into OS X , the Bluetooth icon in the menu strip is wonky and says "No Bluetooth hardware detected". Pops back after a minute though and works fine in OS X. Never saw that again in OS X.