Originally Posted by SA22C

Well, it appears that your HPET device is grabbing IRQs and conflicting with your USB ports. I have been fighting with the same issue on a Dell D620 that I've been working on. The best solution that I've found thus far is to remove the IRQ entries from your HPET, RTC, TMR and PIC devices in your DSDT and apply the DSDT USB patch found here:

http://www.projectosx.com/forum/index.php?showtopic=461