Occasionally, when I sync my Tour with my desktop, it wants to reenter all of my calendar entries. I have to delete all calendar entries off the device and re-sync. Verizon hasn't been able to come up with a suitable answer.
Makw srue your default services is set to the same email that is default on your computer. Yes the easiest way is to clear the calander data base and re-sync. This should resolve it for you.
Hmm - at this point, I would VZW tech back and ask to be xfered over to RIM for tech review. Does this happen again after doing restores of a previous back up? the only thing left that I could thing of is that the calendar keeps corrupting some how.
Wow - this stinks. What OS are you running on the device? If you have not upgraded you might want to see if this helps. Wondering if the data base in outlook might be corrupted. Generally VZW and RIM will not tech for this.