iBook Lockups

[Macmadant]

Hey,
recently my ibook keeps randomly locking up, it first started the other day when it got stuck on a blue screen at start-up eventually it came on, but kept locking up, no spinning beech ball just completely froze, i held down the power button to turn it off, i then had to wait at least ten minutes before trying to start up again, if i didn't it would get stuck on the blue screen, then something else weird happened, when i started up it came up with the mac set-up assistant similar to when you first upgrade, so i turned it off again and it went away, so i started up again this time i noticed that spotlight was indexing, despite it already doing that ages ago when i upgraded to leopard, so i thought this had something to do with it, because it kept freezing in the process, but today i turned it on, let it index and to my surprise it didn't lock up, so i went to play world of warcraft, and as soon as the login screen came up it locked up again, i thought that it might be the graphics chip, but the AHT says the GPU is ok, any ideas ?
BTW i am using leopard, it just randomly started, i upgraded to 10.5.1 hoping it would resolve the issue, but it didn't
the specs of the machine are
1.2 GHz G4
Radeon 9200 32 MB
1GB RAM

 

[Macmadant]

Ok, it's definitely a graphics issue, any time i use a game that has graphical effects, such as WoW or big bang board games, it instantly freezes up, and it's not a leopard issue because i've have leopard around a month and a half and it's been fine up till now, but the apple hardware test tells me the GPU has passed the test, so whats up ?