Firewire (IEEE1394) not working

I’ve installed several flavours of Linux on my Sony Vaio PCG-FX805 laptop and none of them will recognise my external hard disk when it’s connected to the firewire port.
Dmesg displays lots of these lines:
814.840762] ohci1394: fw-host0: SelfID received, but NodeID invalid (probably new bus reset occurred): 0000FFC0
su ‘fdisk -1’ dosen’t show it:
Disk /dev/sda: 30.0 GB, 30005821440 bytes
255 heads, 63 sectors/track, 3648 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x90909090

Device Boot Start End Blocks Id System
/dev/sda1 1 96 771088+ 82 Linux swap / Solaris
/dev/sda2 * 97 1529 11510572+ 83 Linux
/dev/sda3 1530 3648 17020867+ 83 Linux
lspci | grep 1394 does nothing
lsmod | grep 1394 displays:
ohci1394 32880 0
ieee1394 102308 2 sbp2,ohci1394
Can anyone give me simple instructions, remember I’m a newbie, which will allow me to check whether the firewire port is recognised?
It would be nice if someone could tell me how to force Suse 11.2 to recognise the disk. The external disk works with USB, but the ports are only usb 1.1, so it takes ages to do anything. It works fine with a firewire cable on my windoze XP PC.