I have a 650 and MCE, and I spent 4 hours trying to figure it out. I called tech support etc. I got the same incompatibility speil... but I tried to uninstall and reinstall, accidentally installed my 600 software - and it SORT of worked - then I figured out what I really did differently. It wasn't the software - it was HOLD THE BUTTON DOWN then Hotsync comes up on your computer you might be able to get away with letting go after it identifies the user, but for me, it works best if I hold it down until I get "finishing cleaning up"

GOOD LUCK~!