This has got squat to do with AGP, Ross.
I've installed OS/2 on other systems with AGP (the previous system in fact) and haven't seen anything like this.
If no OS would load, I'd consider that possibility, but both Linux and XP loaded fine.
As you may have noticed (read the rest of the thread), I've made progress and eCS is up and running, so I'd have to say you're way off base.