Update....
Seems like this unit doesn't hold an overclocked and overvolted 5870's load too well...

The screenshot of the afterburner reporting -48C was the first boot up without eraser... It now runs idle at -28 to -30C. I haven't seen it go down to the -40C area at all after I installed the eraser. What would be making it run hotter@idle now? Maybe it just can't handle the load and is contacting the die perfectly....
I'm using AS5 on the GPU...
I doubt the eraser around the whole GPU die would kill the temps...
As you can see in the first screenshot, fully loaded it is hitting in the +30C range. At stock it peaked in the +20s.