Asus HD 7770 DirectCU

I've been running this ASUS HD7770 graphics card since September with no problems until I started playing Guild Wars 2. While playing, sometimes the game will freeze up for a while then it will resume but with a drop in frame rate (~50 FPS to ~20 FPS). After that if I try to play any other game it will suffer the same FPS drop in performance.

I checked the clockspeeds on the GPU using the ASUS GPUMonitor utility and it shows me that my memory clocks have dropped from 4600MHz to 596MHz. The GPU clock also drops to 300MHz and doesn't increase when I load another game up. Currently using the latest Catalyst 12.11 Beta 8 drivers. Anyone have an idea what's going on here?