Temp never go above 74, but its on [71-72] average.
You may want to make sure the -s tag is working properly, check your GPU utilization. -s0.01 should lower your hashrate by about a third if it is working. Those temps are a bit dangerous if you plan on running that all the time, so see if you can increase airflow.
Make sure you are on the newest version of guiminer or the cmd utility if that is what you are using, older versions don't support the -s tag.
Definitely do as others suggest, and change your flash settings. Also check the version using something like www.mozilla.com/plugincheck/
so that you are on the most efficient version of flash.