The problem could certainly be related to the ports. There are still some troubleshooting steps that can be performed, such as a BIOS update or testing the motherboard outside of the chassis.
If you wish to troubleshoot this problem directly with us, please feel free to contact our support department:
I don't have the USB issue, but brand new DZ68DB with i7 2600 constantly freezes or hangs. I have Raid 1 set up and due to hard reset, I'm constantly having to build Raid, but can't do a thing while raid is building. This is my first Intel MB where I always had Asus previously. The shop has already "solved" it once, but still NFG.