If you have a VIA chipset based motherboard install the latest VIA IRQ Routing Patch
If you still have problems then try disabling 'OnChip USB' in the BIOS. If this helps then contact your motherboard manufacturer to get a new BIOS without this bug. (eg. Shuttle HOT591P motherboards had this problem, but a BIOS update fixed it).
Go back to our BIOS FAQ.
(Examples: how to update your BIOS, how to identify your motherboard)