PixelView 6600GT failing?

My 6600GT is almost 1.5 years old now and when i play 3D games the screen often or sometimes goes black for up to about 5 seconds.

sometimes when i'm surfing the net it goes black for about 4 seconds when i open a new page or switch tabs.

When i'm playing 3D games the screen either goes black for anytime between about 0.2 - 5 seconds. seems to be the longer the screen stays off the less it flickers but the faster it comes back on the faster it goes off again. also sometimes looking at specific things on games affect it worse than other things.

After this problem started i updated my video drivers and nForce drivers.

any ideas? could it be a software problem?

Whats your power supply? (not just wattage, model please)

EDIT: And yea check to make sure the cooler is clear of dust and is working properly.

I have a question. I've been using a geforce 6600gt pcie 128gddr3 for about 2 years now. I used to have a 15" monitor but now am using a 19" widescreen monitor.Owh and i am using the monitor at my native reso of 1440X900. So my question here is, does my monitor seems to stress my graphics card??

ok i've tried another monitor and instead of rapidly flickering it looks like a slightly diagonal line of scrambled pixels or a flickering bar also slightly diagonal of something i can't describe (grey colors i think).

pretty much no dust.

and i have a 1.5 year old 400w power supply that came with the case. below is model number

FSP GROUP INC.
F400-A

never done that before
will i need that thermal grease stuff or anything else?

ok i think i'll stop there cause i don't really want to throw money into this one. just found out if i turn the graphics down a bit and under clock the card the problem almost completely vanishes then after a while i can put it back to stock speeds without any problems. (maybe cause i have the always use max fan speed check box checked now).

ty for the help random

note to self don't buy pixel view.

could you please send me a link? i couldn't find it