Showing wrong CPU Speed

I have an ABIT BD711 motherboard with an Intel Pentinum 4 2.4Ghz processor. Recently my machine would just freeze both in windows and in Linux. I did some quick research and I found that my BIOS was old and I should update it. I updated it successfully, meaning the computer came back up, bu now it is reading my processor speed as 1.8Ghz and when I use the SoftMenu III setup and try to force back to 2.4Ghz it say cpu is not workable. Can anyone help?

I loaded the optimized default settings in the BIOS and it reset the CPU speed to 2.4 GHz.