I had the same problem. The TRUE isn't truely flat, and the intel IHS is even worse, so it's not making contact with the IHS very well.
Edited by nettwerk - 5/17/08 at 12:11am
You will need to Lap your TRUE, and most importantly your cpu IHS.
I now idle at 28 deg on 2 cores, and 30 deg on 2 cores... load between 46-50 on each core at 3.4Ghz, 1.32v.
before I lapped them I was idleing 40';s and loads in the 70s.
It really isnt very difficult to do there are plenty of lap guides, and specifically on lapping your true you can watch this video. You will find lapping your CPU is much easier than the heatsink because its so much easier to hold and manipulate. It took approximately 1 hour to lap the cpu, and around 3 hours to lap the TRUE.
Don't forget to cover the contact area on the back of the cpu with masking tape, so you don't get copper particles and stuff on them. I personally like to tape the sandpaper to the glass as well, you can buy a large sheet of glass 12"x 16" from like LOWES for $3.00, and you can get a few sheets of each grit for $3 per grit, so around $20 total cost to do everything.