Damn, sorry, I forgot about this thread. It's all sorted now, the person whose iMac it was knew a little bit more about Macs than I thought, and so asked if I could update it to 10.3. So I did, and now all is well.
On a side note, I've never done an archive and install before, always opting to format the drive first. But it was mighty painless, resulting in a clean system of Panther with all of her settings intact. Shan't use it on my own machines, of course, but nice to know it works as advertised.