m17x r3 possible graphics problem?

Hi all

I have an r3 with the following specs
I7-2820
8GB Ram
128GB SSD
ati 6970

i bought this used on ebay, it still has valid warranty for another 5 months. But, most recently, i've started having some graphical issues. I was just using firefox, when suddenly the two pages i had open looked like graphical error1.jpg. As you can see from the picture.. just firefox pages are messed up. The taskbar, and desktop still look fine. This has happened twice, and either i can ctrl+a to select everything on the page to get it mostly back to normal, or close the window and reopen firefox. I got the two pages back to normal, and opened 2 more pages, when i noticed whats shown in graphical error2.jpg. I have also seen this once or twice happening to context menus, but it usually fixes itself immediately.
I have run alien autopsy, and the esa diagnostics. Both of them find no problems. Although, i can't be certain of this, i think this has happened after i have switched from using integrated graphics, back to the 6970. Not right away, after a short amount of time.

So, my question. is this a problem with the 6970, or perhaps some other component. Given dell's track record with customer service(which tends to be hit or miss) I would hate to start a ticket, only to find it was something simple that i could have fixed. But, if it is a problem with the 6970, then i want to get it into Dell before the warranty expires.

Any help, suggestions or input would be appreciated.


Thanks