I am not sure what it uses as I have not opened up the case, it will invalidate the warranty, we bought it from ASDA which means returning it will be a doddle, they give a full refund even after the first month.

It fails to record at times, some times it crashes when he try and delete recordings, some times it records but won't play back. A laster fault does indeed sound very likely.

I am not sure about pre recorded ones.