I have the same issue. I went through 2 levels of VZW support before getting to Blackberry support. VZW was very friendly and willing but unable to resolve the issue. BB support knew the issue exactly. It's a bug. Working on a fix, but no date scheduled yet. My workaround is less than appealing, but it's all I have. I never make calendar changes to my BB - only in Outlook. Before I sync, I first clear out the calendar database by resetting the device calendar (link below). I then sync. All other Outlook databases (memo, todo, contacts) sync fine.
Resetting Calendar - KB04950 http://www.blackberry.com/btsc/searc...200%2081878745