I recently OCd m q6600 to 3ghz. I ran 3dmark06 twice successfully and without anything bad happening. I found out about prime95 and how it is a great test to see the stability of an ocd CPU so i gave it a go. As soon as i ran it my CPU temps skyrocketed to about:
I have a Q6600 OC'd to 3GHz (stock volts) and my temps are approx 55 degrees under load. I only see 70 degrees when I push it to 3.6GHz. I am using a Zalman 9700 cooler.
I think you should try reseating the cooler if you haven't already with Artic silver5 and examine airflow in your case. You have a reasonable cooler that should definitely keep your CPU cooler than what you are seeing with that OC (as long as you don't keep your PC in a sauna. i.e high ambient temp).
Alternatively, if reseating etc doesn't work , you may just have a CPU that gets hot. That said I would still think you could get to 3GHz with a Q6600 without seeing the solar flare that you are currently.
Good luck and check back in with how you get on. Also, you might want to read Computronix's guide to temps, so you have an idea of what is safe for your CPU, he is the guru of all things hot. It's stickied at the top of the forum.