I finished lapping my heatsink and IHS on my Dell 8400 and now the temperature controlled fan is alot more behaved. Before it would keep spinning up and down making me go nuts. This is a known problem on the Dell forums. I have 100 windows open in Maxthon right now with 30-50% cpu utilization and the fan is steady.

Also, when I was finished I still had a lot of marks left on the heatsink and IHS but people in this thread don't seem to have them. Is it just the pics or do I have to lap longer?

Big thanks to everyone here.