please help...

after writing a ghost 2003 image of my system drive to my lacie 250gb d2 firewire/usb2 drive it is not found in my computer and displays yellow exclamation mark and "code 10: this device could not start" in device manager.

this is when connected via firewire. via usb2.0 however it works fine.
also at work the firewire works fine through a soundblaster ieee1394 port.

have tried deleting, uninstalling and rebooting, adding hardware etc...

it's worked fine for several months via firewire.

any advice? strange one this...
thanks in advance for any help