At various times during the day, all is well: ical, Entourage (on my iMac), my iphone, MacBook Air are all synced beautifully. Then, whether I've changed anything or not, the automatic sync kicks in and when I next check, calendars on my iphone, MacBook Air, ical are BLANK. And they can remain blank for a long time. Eventually, the data (that thankfully remains) in Entourage on imac is synced with all of the above. Note, the data remains in Entourage, but that in ical is gone. What I don't understand is whether MobileMe is designed to wipe everything clean and then reinstall the data form the cloud each time (seems incredibly inefficient and risky). I haven't been able to get onto the Calendar function on MobileMe except for the very rare success late at night or early in them morning. My impression (from seeing blank calendars in my own devices) is that MobileMe is wiping all the data off of them (perhaps to compare it with what's in the cloud?) and only after quite some time (several hours at time), the data in ical reappears. For the time being my Contacts are working fine and data remains in Address Book, iphone, MobileMe, MacBook Air without a problem - but the calendar is a disaster. Can anyone tell me whether MM is supposed to work the way I'm seeing it work - and if not, what I can do about it?