Core clock on 7970 GHz goes up and down while mining.

Hi folks, I recently picked up a 7970 GHz edition graphics card using the money made from my 6950. While this is quite exciting, I noticed that the new 7970 has a "high performance" mode from AMD that sets the clock to 500 MHz when idle/ low usage and it goes up whenever something starts really using it.

My issue here is that it seems to revert back to 500 MHz when it gets hot (around 96 C). Then seconds later, it will jump back up to my current clock (1100 MHz). This is all in GUIMiner, is it an issue with the miner, or this "high performance" setting? Anyone else run into something similar?

You can see what I'm talking about here.

Thanks in advance!