Well, you need to check some things in BIOS. First, go into Advanced/CPU Configuration and set PECI to DISABLED. Also, check your Jumper Free Configuration in the BIOS and set AI Tuning to Auto and DRAM Frequency to AUTO. Now go to the Power section and select Hardware Monitor (takes a few seconds to read the fan RPM). For now, set CPU Q-Fan Control and CHassis Q-Fan Control to DISABLED. When you reboot, your fans (all of them hooked to the MB) should blow as hard as they can. After you do some experimenting, you can set these back to Enabled. I use the PERFORMANCE profile and it is still quiet.
OK, now you are as cool as you can get. As long as you took the previous advise and double checked your heat sync install. Also check your chassis fans to make sure they are plugged into the motherboard not into the power supply.
Boot up and load Windows. Download
Core Temp 0.94b and run it. This is the best indicator of real core temps I have found (I've tried them all). If you want to futz around, intall and run ASUS PC Probe II from the ASUS CD and compare its temps to Core Temp. The ASUS CPU temp is always cooler. At idle it is more off than at full load. If PECI is enabled in BIOS, the ASUS temps will be much less than the Core Temp (as much as 16C less at idle). That's why you see all those posts bragging about 30C CPU temps and I can't get mine below 40C. Anyway, let it idle and see what the temps are. Your fans should be going full blast because you disabled Q-Fan in the BIOS. This is as cold as you can get. Stock, with no OC, I idle at 41-43C.
Now, download
Orthos Beta (Stress Prime). Set it to stress CPU and run it. This will put both cores at 100%. Watch the Core Temp data and see where it stabalizes. Mine stablaizes right at 56C with everything stock and the fans at full speed.
Now you can go back into the BIOS and set the fans wherever you want. As mentioned, I use the PEROFRMANCE setting even while I'm overclocked. At 3.2GHz, 400 FSB and stock voltages, I am stable and idle at 48C, 64C full load. That's good enough until the new Scythe Infinity cooler gets here.
Other programs that I find useful:
Intel Thermal Analysis Tool (another temp monitor. Closes matches Core Temp. Other useful toys)
Speed Fan 4.31 Nice tool for temps and allows you to adjust fan speeds on the fly [as long as Q-Fan is disabled in BIOS])
Hope this helps. Keep us updated on where your temps are.
Tom