At least Asus' P4 series don't have this problem.
I'm experiencing some throttling problems here too. Going to switch to Asus real soon (P4B533-E).
I notice for BD7, the temperature read by the mobo's probe are about 11ºC higher than what my external probe reads.
When my probe reads 56ºC, my board reads 67ºC. On Intel's website, they say the Max. Temp. Junction is 67ºC for 1.80A, and I get throttled back occasionally a little.
I am suspecting the Winbond 83627 hardware monitor chip that is casuing the problem, but I'm not ruling out the clock generator either (someone told me got to do with the gen. also).
I have emailed to ABIT a dozen times, but I just got one reply. In that e-mail, the person said, "there will be BIOS updates at the end of the week." True enough, BD792.exe for my BD7 was released, but problem's not solved. I replied immediately, but until now (more than a month), nothing's been done, neither got reply.
HTH.