Intel DG965WH Slow Boot with CPU Fan oddity

I usually keep my PC on but I noticed recently that when I reboot, it is taking much longer at the inial bios screen than it used to.

I have an Intel DG965WH with E6600 2.4GHz and 3GB RAM. When the system boots, I see the Intel splash screen and there is a small box in the lower right corner with a two digit hex number. It used to zip through a sequence of HEX numbers and then continue on to boot into Windows XP.

Now, it hangs with the hex code '58' and sits there. As I wait, I hear a fan start to slowly wind-up in speed until it sounds like it is humming at full throttle and then my boot up continues as normal. After I boot, I can hear the fan gradually slow to a whisper.

I opened the box up and can see that this is the CPU fan and it is always running but during this boot, it slowly spins up to high speed before my boot continues.

Why is my MoBo doing this? Are the '58' code and the fan spin-up related? This is a pain in the butt. The fan spin-up and and hang on '58' lasts for over a minute where it used to just buzz past the initial Intel splash screen.

Any ideas?

Thanks in advance!