is my video card crashing?

[Conceptor]

after 30 min or so of playing i start to see patches of colors in the sky, then a lil while longer the screen goes black followed by this sound that sounds like something screeching then ripping. and usually the temp of my comp is 90 degrees at that time.

i hav one fan in the back blowing in, and one side panel fan blowing out, as well as the fan on my 9700 pro blowing on the card. (just so you knew)

i recently bought a zalman heat-pipe cooling system for it with the copper lube/coolant/whatever its called (like arctic silver) will this help and allow me to actually overclock it too? (i havent overclocked it yet)