Working with our tech support I found the problem. Calendar entries that repeat were causing the problem. I deleted all of the calenar entries that repeat, go to service books and delete and undelete CICAL service book, pull the battery and make the berry reboot, and the calendar works fine. I was then able to go back into Lotus Notes and re-enter the calendar entries with repeats and they came through just fine.
Since then it has worked OK - [keeping fingers crossed].