This might be a stupid question, but I'll take the risk
...I have an Olympus E-500, but decided to try a newer Olympus and since I'm very pleased with my E-500 I decided to go with a (second-hand)E-520.
Now. When I turn the E-520 off, there's a little sound from the camera (like a little drum-roll). I don't know if this is some kind of a cleaning process, or if there's something weird with the camera. I bought the camera from a re-seller so there's a 3 month guarantee.