Sounds like you aren't able to exhaust the hot air fast enough when multiple components are being taxed simultaneously.
Components are in a NZXT H2 Classis chassis, side panel off, GPU temps never go above 73*C when mining with the side off. It's an XFX DD 7970, and the I7-950 is under a Corsair H80 closed loop cooler.
Touche' guys. I just took a look (it's mining right now) and sure enough, CPU temps are hovering around 50* C instead of my normal idle temps of 38-40* C. Never noticed it before since I start the miner, walk away, and check in on 50btc from time to time to make sure it's still hashing.