Help please on whats backed up

I've religiously backed up my Playbook since I bought it and felt safe that I'd be able to recover from most disasters. However after downloading the latest seemingly untested update I lost all entries in my "local" calendar. Thought OK just do a "restore" this however did not bring back my local calendar entries so my question is what did I do wrong. When doing backups there did not seem to be any choice of do you wish to back up "local" calendar entries and again no choice of do you wish to restore calendar entries. Please will someone explain are they backed up and how? Needless to say like lots of others I'm amazed that RIM are so incompetant to let this happen it's not good for bussiness.

Holgate001