your components are all good unless something is damaged its not them. somewhere along the lines you must have the wrong drivers or a bad setting or something. just go through every detail possible and try to pinpoint where your problem is. also have you updated your catalyst drivers.
2.8 p4 @ 3.15 900fsb, 4 sticks corsair xms cas latency 2-3-3-6 256mb each, leadtek 6800 gt 256mb @ultra speeds, gigabyte ga8ik1100 mobo, nec 3500a 16x dual layer dvd burner, tdk 48x cd burner, wd 74gb raptor hd, windows xp pro sp2, dell 2005fpw 20 inch widescreen lcd monitor