You could try fiddling about in the BIOS turning off all kinds of Plug and Pray settings and assign IRQ adresses manually. Or, maybe easier, try and override any Windows automatic IRQ settings and give unique adresses your self. We all know how unpredictable Windows can be!
To find the hardware causing the IRQ clash have a good look on what devices are running in normal-mode that are not running in Safe-Mode.
Oh, and as someone pointed out... make sure to have the latest available BIOS installed.
