Palit GTX260 Sonic 1792MB BIOS Tweak

Hi..

i need a help from you guys that mastering this part

i have Palit GTX260 Sonic 1.8GB.

the problem is this card doesn't have 2D clocks.
It always run at almost full power..
so the idle temperatures is about 52°C. My room temperatures about 24°C (use air conditioner)
how can i make this card to have 2D Clock so if i'm just using opera, it'll reduces it's core clock...
and if i'm palying some 3D games it's core clock will be back to default..

last thing... anyone know how to change the voltage ? im testing 3DMark06 this morning (GMT +7)..

core 695Mhz
Mem 1202Mhz
Shader 1499Mhz

it give me 17.195 3DMarks Score..

then... a few hours later... i'm rasing the bus speed for the processors to 4320 Mhz.. then the display shows some artifact...
at the first i thought it's must be the processors... then i reduce it to 4.2Ghz... but still the same...
last thing i tries the "morning" configuration... still got some artifact...

so i test again
E7400 @ 4104Mhz (9X456) 1:1 to ram
but the gpu on default speed...

it gives me 16.186...


so i think the problems not from my processors...

any one can help ?
i'm new to graphic card overclocking.. especially BIOS Flashing...

thanks for coming by... and sorry if my english is bad

@r_manic

Thanks for the answer man !

but i want to tweak my BIOS..

http://www46.indowebster.com/down. [...] ffd49e.zip

that is my standard bios.. could you guide me ?

i've been try... but no effects. Change the voltage, but read on the EVGA Voltage Tuner still the default voltage.