Urgent Help Needed: Is my new GPU bad?

I purchased a refurb AGP Leadtek 6800GT off newegg a few days ago. After the card arrived, I installed it with ease.

Before we begin, let me dismiss a few easy fixes people might point out or suggest.

1. The card feeds off a 450watt PSU with only one optical drive hooked up to it. NOTHING on my comp is overclocked.

2. I've updated drivers/dx9 over three times.

3. The card shows no signs of overheating -- it idles at 52c.

Screenshots similar to THIS depict what my comp looks like seconds before a crash:



I've tested both Oblivion and 3dmark2006 (the same thing happens in 3dmark06). Each of these events occurs only minutes or seconds into gameplay. I'm almost sure my card is dead and I need to RMA it tomorrow.

Any advice, confirmation, or feedback would be appreciated =).