Video card problem ??? No idea what this is

[imported_SC4RF4C3]

I am having a weird problem out of nowhere for some reason when I start my PC every so often my screen looks all scrambled even with a reboot samething just a different color pattern the only way I can fix this is to clear cmos and reboot and restore all system settings this card worked fine for 3 months then I start seeing this happenening, I have no idea what this is or what may be causing it.
ALSO I never done anything other than run everything at normal speeds.
HERES is my system specs....
BFG 6800 oc
asus a7n8x 2.0
athlon xp 2500
1 gig of DDR ram.. corsair
I also have a dvd writer and cd burner
350 watt power supply

 

[imported_Kensai]

Who made the power supply? The power supply could be too weak if it's a generic 350W, or it could be a cooling problem.

 

[imported_SC4RF4C3]

"CASEDGE" is the name on the power supply, I was running a 9500 pro on this machine no problem then installed this one and after 3 months this crap.
I also did a new install of windows when I did this work,

I never seen this problem so I need help in figuring this out.
Not sure about the over heating as it did it the first time I turned on my machine today I finally got it back up thats when I came straight here.

 

[imported_SC4RF4C3]

I take back the power supply its a 300 watt power supply.

 

[Silversierra]

That may not be enough power, maybe it could cause issues if it was under powered.