It worked fine for the first couple of days, though, sluggishly at best. Now MobileMe almost consistently locks up (Finder)on my Mac-Pro whenever I modify/move files on MM, forcing me to power off the machine via the power button. NOT COOL! I gave up and shut off the service on my Mac Pro for now. Does anyone else have this problem? Mysteriously, it works fine on my iBook G4 under Tiger. Apple support wasn't able to lend any help. fyi: I'm only syncing iCal, Address Book and a few documents. No iPhone, website or iPod Touch.