ATI 4670 driver causing lockups? HELP

i recently bought this card and its been truely amazing for the price. When i first got it i overclocked it using rivatuner about 50mhz on both core and memory. ran smoothe. i can almost gain 100mhz without locking up. i'v updated the drivers according to ati and now i can barely overclock it without locking up when playing games. it'll run smoothe for a while but then it locks up. Temperatures are super low and this card is available to clock to 1200MHZ!!!!!! on both ends so i know i can hit 900+ atleast i think. im currently stuck at around 805 core 875 memory (factory 750-850) i rolled back my driver to hit these clock settings, with the latest driver i can hardly oc at all. i was wondering whats a better driver to oc? my card hits about 50C under load at the current clock settings so i know i got alot more to gain without having to worry about temp. This card can be a beast if i can find a good driver to let it rock out like i want it. any ideas would be appreciated.

note: im using ati CCC to force fan speed to 100% at all times, other then that i dont use any of the other settings.

http://www.newegg.com/Product/Prod [...] _-14161287