PN58A650 Looks like im getting burn images

[stonkeye]

Hi all, i have PN58A650 and im starting to notice some shadows on the screen where images look like they have burnt in.

Any one else have this issue, the set is only 5months old and i notice even if a still image has been on for only a few mins.
Like the PS3 start screen with the icons.

The image corrects itself after a while so its not a big issue at the moment but i thought this set would no suffer this sort of effect.