No, madmax's solution will work just fine.
@cinemo:
I'm really gutted for you having this issue. It's a real bummer when your drive goes fut on you, especially as you were *about* to make a full backup. It sounds like the hard disk itself has gone south somehow or other. The data likely won't be recoverable if it's gone that far, and every time you start the disk you are probably doing more damage.If it's head banging (it's a technical term), then it's likely the surface has sustained damage (which confuses the heads), or the drive's formatted data area is corrupt (this causes continuous retries). The latter would point to MacFUSE trying to use the wrong FS type on the drive and screwing the format up. I have had this issue in my Powerbook G4 and the hard drive works ok following a fully Zero erase but the OS on it totally died. That said if you can get a fresh hard disk for free you may as well, it's best not to risk anything with hard drives, then have to go through it all again 2 months down the line.
I guess this is why Apple put Time Machine in Leopard, you just never know WTH your hard disk is going to do to you... :\
Out of interest what vendor is the hard drive from (if you know)? Seagate drives have a 5 year warranty and, save for one batch that recently found their way in to some Intel machines, they are very reliable in my experience. I know the Mini G4s used mostly Seagate Momentus 4200 RPM drives (5600rpm in the later 1.5s).