I now have a copy of Leopard and have been looking into this again as I really really really really want to get this working - here it says someone has got it to work on a G4-upgraded iMac G3 - how is this possible, as the iMac G3 also suffers from this "cannot find platform drivers" error doesn't it?

Where exactly are the platform drivers, eg what kext, if ones appropriate for older Macs need to be inserted into the Leopard disc? Does Tiger have platform drivers for the Beige even though it wasn't supported, as none of the XPF extensions look likely to be such a thing?