I think my iBook is on it’s way out.  Nick (who has been perhaps the most unfortunate person in the world with iBook logic boards) has confirmed that my beloved iBook G4 is showing all the signs of a logic board failure.  I’m desperately hoping that it’s still in it’s warranty period (and that I can get all the paint off it), but I’m pretty sure that it is now out of the warranty.  This means I may have to shell out rather large sums of money for a new iBook - either that or petition Apple to extend the logic board repair program (again) to iBook G4s.