To donmarkoni & leo27
Could you please try the 32bit version and let me know wether there is any difference? I've received an email saying that in 32bit version it reads the frequency correctly.

To gymenii
Core Temp's new algorithm basically measure the CPU's active clock cycles, and calculates the frequency based on that. Even if you disable speedstep, when the CPU is idle it skips clock cycles to save on power. Since this is the proper way to read clock speed for the Core i* series CPUs I thought I'd implement it for the C2D chips as well since the same code just works on these chips too.
I may have to revert back to the old way of speed detection for those processors, I'm still thinking about how to proceed.
Try to run Prime or superpi, you'll see it clock right up.