iMac G4 HD problems

[Griffo]

I have two (at least) problems:-

1. The imac won't boot from the resident drive (have tried all the usual fixes), so I've installed OSX onto a firewire drive. When booted from there, I've tried to use Disk Utility to repair the resident drive (which shows as 2 partitions). Selecting the second partition, Verify says 'Keys out of order, this volume need to be repaired' - Repair says - 'rebuilding Catalog B-tree' then 'the volume could not be repaired'. The primary partition only offers Verify, which also reports 'Keys out of order'.
Does this mean the HD is completely wrecked or is there some software somewhere that may repair it?

2. The firewire drive is only mounting one out of 3 partitions (they all show when attached to another imac). Using Verify says the volumes apear to be OK but Information says they aren't mounted. How do I get the other 2 partitions to mount?

I really would appreciate some help please.

[Griffo]

doesn't anyone have any ideas on this one please?