Screen burn-in and display sleep issues

Hi,

So, I purchased an Apple 23'' Cinema HD display two months ago second-hand, and I'm beginning to notice some problems with it.

The first thing is that the display seems to be extremely prone to sudden burn-in of bright images over a short period of time. For example, if I leave my browser open on a white page (such as Apple Discussions) for a period of time, perhaps 15-20 minutes, there is a noticeable after-image left behind when I move the window or move a darker window over the brighter one. It's not permanent by any means, but is frustrating.

The second thing is that, recently, if I sleep the display by moving the mouse into a hot corner, it will turn off the power to the built-in USB hub (which powers my keyboard and mouse) also, rendering any attached devices inactive. If I press the display's power button to prompt it to come back to life, the power light will sometimes (but not always) come on briefly, then die, and the display will stay off.

Are these typical problems on an end-of-life Apple display, or something else?

SiR G.