My aunt gave me her old MacBook Pro, but unfortunately it has a few issues. The main problem is that lines appears after I use it with applications that heavily depend on graphics, but they don't necessarily appear in that window.

I also figured out that these lines appear with the windows, so the cursor goes over the lines, and menus and other windows also overlap them. If I take a screenshot of the window by itself, no lines appear.

It seems obvious to me that this is a driver-related problem. Unfortunately, there are no updates or anything for the driver. At first I tried asking for a solution at Apple's forum, but they were only able to figure out that "something is wrong with the video card".

I checked the MacBook with an Ubuntu disk, and the screen seemed OK.

I've uploaded some photos to my Picasa account to show the symptoms.

Recently, I've also noticed the screen flickering when using applications that need high performance graphics, like games.

Also, the MacBook Pro came with Mac OS X Tiger, but she upgraded it to Leopard (she only brought the Tiger disk with her.)

What can I do with this?