but since many people boards which had this issue now have BIOS's to correct it, I suspect that EPOX can do the same (assuming they get a good nudge in that direction).
Problem with that is Epox have had dual core BIOS support since end of June and if there was a real USB 2.0 /x2 issue that a simple BIOS update could fix, well it would of been fixed by now,also in those threads of yours you'll still have people with no USB 2.0 issues with their dual core CPUs,so conculsion wise it is hard to point the finger.
The way I see it at moment seems to be very hard to track down the cause,some people have problems while others do not,if it was a dual core problem with USB 2.0 then all X2 owners would be getting lockups to some extent with their high speed devices.
Anyway here is my USB 2.0 irq settings to start the ball off.
At bootup USB 2.0 controller showing IRQ 12,
in Windows(System Info)I have the following,
IRQ 0 System timer OK
IRQ 3 Communications Port (COM2) OK
IRQ 4 Communications Port (COM1) OK
IRQ 6 Standard floppy disk controller OK
IRQ 8 System CMOS/real time clock OK
IRQ 9 Microsoft ACPI-Compliant System OK
IRQ 11 NVIDIA nForce PCI System Management OK
IRQ 13 Numeric data processor OK
IRQ 14 NVIDIA nForce4 Parallel ATA Controller OK
IRQ 15 NVIDIA nForce4 Parallel ATA Controller OK
IRQ 17 Creative SB Audigy 4 (WDM) OK
IRQ 18 NVIDIA GeForce 7800 GT OK
IRQ 19 VIA OHCI Compliant IEEE 1394 Host Controller OK
IRQ 20 NVIDIA nForce4 Serial ATA Controller OK
IRQ 21 NVIDIA nForce4 Serial ATA Controller OK
IRQ 21 NVIDIA Network Bus Enumerator OK
IRQ 22 Standard OpenHCD USB Host Controller OK
IRQ 23 Standard Enhanced PCI to USB Host Controller OK
As you can see nothing is shared,yes I did install the X2 driver and Nvidia SW IDE driver FYI.