Nokia N82 Camera problem

Hello everybody. Today I bought a second hand Nokia N82, and now I revealed something wrong.. When I start the camera (5mpx), it starts OK, but after few seconds the menu hides and I don't see even the focus rectangular. I can't switch to Video mode, nothing.. I can just make photos, the red light and the xenon works fine, but I can't see the options, which disappear. I upgraded to the last FW, but the problem is the same.. I tried *#7370#, "*" "3" "green phone", but I didn't find solution. When I press left/right, the zoom works. Everything else is not working.. I don't know why the icons are hidden (because when I start the camera I see them for 2 sec, and then I can do nothing to bring them back) Any ideas? See you.