Problem clocking Connect3d x1950pro memory freq

[Z_Dash]

I'm getting stucked at this clocking
Its a Connect3d x1950pro with AC accelero cooler.
Stock 600core/700mem.
Tried using both Atitools 2.6 and 2.72 beta.

Tried pushing core to 685mhz no problem......ran 3dmark05 alright. Pressed set default and gfx lockups. Rebooted PC and tried pushing mem freq.......just +0.5mhz only and apply. The gfx just locks up.
Using Catalys driver 7.8 now.

Anyone can help if anything i could do to push my mem freq?

Btw temperature is 47deg at idle at stock clocks.
Tried running 3dmark05 with core at 685mhz and temp = 61 at load.

 

[Morgoth]

try using overdrive in ccc first then save that sollection in atitool that might help

 

[mitsirfishi]

have you tried using rivatuner i know on my asus card if i touch the memory in atitool or overdrive it just locks up but when i used rivatuner for my card i just wacked it up got around my lockup problems