We have a 7230 user who has multiplying recurring meeting notices and cancellations. Any ideas on how to eliminate this?

Are you on a BES server? I had a problem similare to this... When i turned off the wireless synchro on the calendar and then turned on again... appointments often came back doubled... I wiped the user calendar and then turned on again the wireless to solve the problem.

Could be an oldie but a goodie. Check the version of CDO.DLL that is running on the Exchange server and the BES. They must be the same (and at least at a certain level). There is another recent thread on CDO.DLL.