overclocking my radeon 9600

a while ago i got this radeon 9600 from best buy. it plays game really well but Im having trouble overclocking it. whenever I clock it too high it just freezes or artifacts, and I can really get my fps up. I especially want to get my fps up though cuz i just got counterstriek-source and can only get around 30 fps and with the tweakin ive done so far it only up to about 40 fps. also i have overclocked my card a lot more then sum of my friends and they get over 100 fps anyone know wuts wrong?

Welcome to the forums.
Each video card is an individual challenge to overclocking. Some are just better than others. One constant is the amount of cooling you give the card. The cooler the better. It is possible to overclock too much and lose fps.
You have to go up slowly and test between each increase to get the optimal overclock or use a tool like ATItool or ATI tray tool which tests for artifacts for you. ATItool is more conservative and will give a lower, more stable overclock.