Dark Corner On iBook G4 Screen

[rolex54]

I recently noticed a dark corner on my iBook's screen
I am not exactly sure what it is
It does not show up when there was a white screen from a movie playing in fullscreen
Anyone have any ideas??
http://i35.tinypic.com/12166tk.jpg

[super_kev]

One of our iBooks had dark corners, and it was due to the frame slightly pinching the screen. That could be what is happening.

[iShater]

That looks like a screen shot, if it was physical, it wouldn't show in an image file.