Along the same lines as this thread, I've a bit of a problem.
I moved my 160G drive from an old G4 tower (533DP, for sale sans hard drives, keyboard and monitor ifn anyone wants it), where only 128G was recognised and formatted.
Is there any way to recover the missing space now that I've converted it to an external Firewire housing? Could the same utility tear down the existing partitions, as I no longer wish it to be partitioned either.

Javarod's problem has probably been solved by now (or not), but for reference for anyone else reading here now, all he needed to do was to initialize (erase) the 160 gig drive after he moved it to the Firewire enclosure. This will work as long as the enclosure isn't so old as to not support drives larger than 128 gig--for some of these older enclosures, not even a firmware update will help them see larger drives.

And I can confirm the consensus about drive sizes vs Mac logic board versions: I work with a lot of Mac models, and did experiments on each of the models being discussed. The Quicksilver 2002 logic board is the first that can see all of a larger-than-128 gig drive, as a single volume, connected to the logic board's ATA hard drive bus (not the optical drive bus, in case anyone is getting picky and tries their hard drive on that bus). For older Mac models, use a PCI slot ATA controller board, preferably one that's ATA133 for best compatibility (proper read/write, etc.) with large, newer drive models. Don't use an old ATA66 board--it might work for some drives, but not others (probably not the drive you decide to use).

I know this thread is old, but maybe this additional info will help someone, so I would like to share a link with you that I found:

http://support.apple.com/kb/HT2544?viewlocale=en_US

I am German and I do not know wether I have understood everything under this link, but as far as I got it, it says:

There are to ways:

1. you have a mac that allready supports drives larger than 128GB (or 137GB respectively), which is Mac from until June 2002.

2. If not:
a) install an OS X, higher than 10.2 and you can utilize a bigger harddrive
b) For OS 9 Users, they should use OS 9.2.2 and make partitions of not more than 200GB each. (Example, if you have a 320GB HDD make one with 200GB and one with 120GB)

2 b) contradicts one of the posts above so I guess I got something wrong, huh? Or the point is, that the 200GB per partition thing is executable in OS 9.2.2, but if you have lets say OS 9.2.1 installed and use a 160GB HDD it will use the drive but somewhen it will write out of the 128GB space and the drive will get problems. (concerning the last point I got an answer from hitachi, they told me I would have to buy a 120GB model, because I will run into problems with a 160GB HDD later, though in first place everything will look fine.