My son's Pbk G4, 400, with 764 Mb Ram, running OSX 10.4.2 cannot start up. He gets a grey screen (multi language restart instruction).
He apparently ran TechTool Delux when it was slowing down.
Then after restarting from a Start Up Disk and running Disk Utlitlies - repaired preferences - which seemed to work. He then ran Repair Disk, which resulted in following messages:

"Repairing disk for "Macintosh HD"
Mounting disk (S, "checking HFS Plus volume.",0)
Invalid B-Tree node size
Volume check failed.
Error: The underlying task report failed on exit (-9972)
0 HFS Volume repaired
1 Volume could not be repaired.

He has a mirror image back up from a couple of days ago. Can someone please point us in the right direction for our next step?
Mike