My HTC One X on AT&T is connected to a corporate email system. Earlier this week, appointments started dropping off my calendar at random. I probably have about 10% of the items that should be on the calendar and I'm not sure how ot resolve. Email coming from the same system is working fine. The corporate email system is Exchange 2010 and I've confirmed there have been no changes to Exchange (I work in IT). I've also tried removing the Exchange account on my phone and when I add it back, I have the same problem. Any ideas? Thanks!