desktop 'tv static' problem

Hi fellow MAC users, My Imac has recently developed a problem with the desktop at both startup and when I login after the screensaver is activated. The desktop wallpaper and icons appear but a grey tv static covers most of the screen much like an unplugged cable in you tv(without the movement, rather as a still pattern). I can fix this by dragging an icon accros the screen or opening a program whereafter the window that is opened deletes the pattern behind it.'ve installed all updates but nothing changes.Once gone it stays away untill I leave my computer, the screensaver automatically starts and voila, there it is again.


Any thoughts?

jannssenn

 

Thanks for the tip, trashing everyhting in the cache worked like a charm.