Check the connections to the Mobo (page 2-3 in the manual for the layout) Check the manual for the pin labels (2-28) and match them up. The USB plugs for the front is on the side farthest from the CPU would think you didn't connect it to the firewire pins, you would have fried something then.
Then boot to the bios and check how many USB's are enabled and how fast. If there arent as many as is supposed or if you cant change the speed, something is wrong. If not, save and boot.
If it works, great. If not uninstall the USB's and reboot. It should find them by themselves, unless you inadvertently overwrote them with the wrong drivers.
If none of this works, Tigerdirect has them on sale for $299.99 - Just kidding
