[iBook] Apps quitting

[Tom Meade]

Hi - It started with Safari, then Firefox, the Mail followed by other
apps quitting soon after opening on my normally stable G4 iBook
1GHz/768MB. So I ran DiskWarrior for a new directory, Disk Utility
to Repair the disk and then Repaired Permissions. And it improved -
Firefox ran but Safari still quit. Repeating the disk tests results  
produces
"Needs Repair" all over again - same with permissions. Is this normal
are is this a sign that the disk starting to fail?
Tom