All,
I rarely even quibble with Wolluf, but my own experience:
Note the similarity of the issue: it stops at first boot, works fine thereafter.
Thoughts:
It is a heat related issue as Wolluf described, but not an over-heating issue. Pull out every device you have in a PCI and/or AGP slot and clean the contacts. At a good computer or electronics store you can find coatings for your gold contacts to reduce corrosion. But pull all of the adapters out, including RAM, use a clean #2 soft pencil eraser, and rub them gently. Clean, and reinsert.
Look very hard at your video board, or any other device with ROM code that needs to be incorporated at startup. Look very closely that you have set in BIOS, if possible, the appropriate settings for BUS MASTERING devices. Look in the BIOS to see that shadowing of the adapter ROMs was not done inappropriately.
My experience has been that the BIOS settings for that PCI slot were not set properly to allow the DRAM of the device to begin a refresh cycle in sych with the rest of the computer.
Look very hard at the Video adapter manufacturer's web site. Do not use the Windows Update proferred device drivers. Go to the OEM chipset driver manufacturer's Web sites for Video driver Updates.
Finally, it might be an issue of bad capacitors on either the motherboard or the power supply. If it works after a reboot/reset, I would leave sleeping dogs lie. Leave it alone as an issue, there are far worse things, and "solving" a sleepy or poor capacitor issue is just simply not worth your time.
Bill Castner