Yeah it's dusted out.Have you dusted it out?
Do not run the card if you can't keep it under 80 degrees. My 7970 started giving me a ton of issues after I hit 95oC once.
Place an 120mm fan in front of the blower and connect it to the motherboard. Set that fan to fun at performance. It will definitely help. Also, as Darren said, replace the thermal paste.
Why do you go about responding to threads that are 3 weeks old and already answered with no response from OP? Seems a bit redundant.