Pearl dies mid call

It is the strangest thing. I can be talking or listening to a voice message and the phone just locks up. I lose the call and pushing any of the keys doesn't do anything. The screen is off, the only sign of life is the red message light comes on constant.
I have to pull the battery to get it to restart.

There is no rhyme or reason, I can't think of any chain of events to duplicate the event.

It happens about once a week, sometimes a little more, sometimes less.

tia

wierd...check the memory...maybe you need to free up some memory? good luck