Just hit a brick wall on trying to update my G5 iMac iSight 20" to 3.17 (currently running 3.16). I'm trying to boot from USB (can't from the optical as it is non-functional), but after the 'quiescence' message I'm getting the following error:

Invalid memory access %SRR0: 00000000.00c02230 %SRR1:100000000.00003030

I've tried re-downloading the iso in case it was a download error, but hit he same problem. Any help would be much appreciated!

Thanks,
Nigel.