Mysterious change in my PC's reported spec - a problem?

[comradec]

Normally the system information in the control panel of my home studio's PC shows the following computer specification:

Intel(R) Core(TM)2 CPU
6600 @ 2.40GHz
2.40 GHz, 3.25GB of RAM

The other day, however, I noticed a slight change to that spec as follows (the difference is shown in bold):

Intel(R) Core(TM)2 CPU
6600 @ 2.40GHz
1.58 GHz, 3.25GB of RAM

The spec information is back to normal now but I wondered if this change might be significant, as I've been having quite a few issues with the system, particularly Explorer, freezing up lately. I've had to reboot or close and restart Explorer using the task manager to get Windows working again after these problems cropped up.

Could this change from 2.4GHz to 1.58GHz, albeit temporary, be a sign of trouble at mill?

I'm using Microsoft Windows XP SP3, by the way.

[Nord72]

Probably the speedstep have been activated and the system set back the clock (power vs. efficiency)