7600GT overheating after over clock

[Skript]

Hey, I'm having problems with my XFX 7600GT. I've overclocked it (using standard fan) to:
http://i5.tinypic.com/835dstx.png

The problem is that when playing graphically demanding games: the witcher, COD4 (only ones i've actually been able to test with) the GPU temp will slowly rise till it gets to about 90-95 then the card will kill itself resulting in me having to reboot. Its summer right now, yesterday was about 39 degrees celcius no air-con just ceiling fan and pedestal fan. Today is about 20-25 degrees and the problem is still occuring. I was just wondering if maybe the heat yesterday was abit too much and has caused the core to fry. the problem also occurs with default clock during gaming. Memory clocks are left default.
Haven't had any temp issues while using my OS.

I've also included a rapidshare link to my system specs:
http://rapidshare.com/files/69396370/cpuz.txt.html

[tkpenalty]

Why is the fan at 0%? Your GPU's fan shouldnt be stopped.

[Skript]

For some reason I have no control of the fan with atitool

EDIT:
Just opened up my case to double check that the fan is working and it is.

[AsRock]

Check for dust in the heatsink maybe around were the fan is. I've seen a few 7600's with the 7800\7900 fan heatsink and they block up fairly often.

[Mussels]

might need dusting or a re-grease.

[Skript]

exert from the log i was running until crash.
2007/11/13 21:7:21 83
2007/11/13 21:7:25 81
2007/11/13 21:7:29 80
2007/11/13 21:7:33 82
2007/11/13 21:7:37 82
2007/11/13 21:7:41 82
2007/11/13 21:7:45 83
2007/11/13 21:7:49 83
2007/11/13 21:7:53 83
2007/11/13 21:7:57 82
2007/11/13 21:8:1 83
2007/11/13 21:8:5 84
2007/11/13 21:8:9 83
2007/11/13 21:8:13 79
2007/11/13 21:8:17 81
2007/11/13 21:8:21 80
2007/11/13 21:8:25 77
2007/11/13 21:8:29 81
2007/11/13 21:8:33 81
2007/11/13 21:8:37 81
2007/11/13 21:8:41 81
2007/11/13 21:8:45 82
2007/11/13 21:8:49 80
2007/11/13 21:8:53 81
2007/11/13 21:8:57 81
2007/11/13 21:9:1 83
2007/11/13 21:9:5 80