Our VP is getting duplicate entries on both his BB and in his outlook calendar. I just booked him in a re-occuring meeting this morning and had him book me in one as well. The duplicates have now appeared for him. They start on the 2nd occurrence of each meeting and continue for the series. They are also in both his Outlook and in his Blackberry calendars
I would guess that the problem lies on the Exchanged side, since the BB server seems to be doing the right thing -- Finding meetings on Outlook and replicating them to the BB.