I think that onboard firewire port may be bad...but not sure how to fix that. Maybe your mobo website has a troubleshooting guide or bios update?
I would just use the front side firewire port or buy another firewire/usb pci card.
-AMD Phenon X2 555
-Western Digital Caviar RE WD2500YD 250GB 7200 RPM 16MB Cache Serial ATA150
-Patriot Sector 5 DDR3-1333 (4GB)
-Rosewill 500W PSU