I updated my device from .167 to .247 today and so far its a marked improvement.
Somehow, when the calendar entries were put on the phone after the update, they were placed in the "Facebook" calendar. The issue is that I do not use Facebook. Those entries should appear on my main email or the device default. I used App Loader and deleted the Facebook application, but the Facebook calendar remains.
I had same problem with facebook hijacking my calendar. There's a bunch of threads about it, but I just deleted the facebook cical servicebook and that deleted the FB calendar. For more info search crackberry for delete facebook calendar
Posted from my CrackBerry at wapforums.crackberry.com