When events reach a month old, my BB calendar deletes them. When I sync with Yahoo, they are deleted there. I have my BB calendar "Keep Appointments" option set to "Forever" but it still deletes them.

The only limit seems to be memory limits. do you have a lot of old calendar entries or other data to excess.

I am short on device memory. I notice that it only deletes events that exist only in the past. If they are recurring into the future it leaves the in the past. I've cleaned off all but my most used apps, but still don't have much free memory. Guess I'll try deleting some more.

Check to see what may be running. Some email apps and text apps run all the time checking servers. BBM and some other do not.
Also GPS services, Blue tooth etc.

upgraded to storm2... that oughta take care of it