I would take more notice of eddies reply, mine was only a meek suggestion!
But to delete boot with dvd search extensions folder.

Would I be right in thinking that you upgraded to 10.5.2 and didn't use Zephs 10.5.2?

Just remembered that when I upgraded I had to delete a kext I can't remember which one exactly but it certainly had SMC in the name.
by the way its a plugin which means it will be inside another kext file