I have been having problems with calendar entries disappearing from my blackberry. Somebody told me it might happen when the device is running low on internal memory. I checked and I have 167,000 bytes free, out of a little over 64 million. I don't have ring tones, music or videos on the device. I keep a minimum number of emails in it; I erase most after reading them.

I only have my address book, and my calendar from which non-recurring appointments older than a week, all of a sudden disappear.

I'm not sure if the disappearing calendar entries issue is related to what appears to be a low memory, so I'd appreciate help on these issues.

Thanks a lot!