I was under the impression that in some cases after control passed from the BIOS to the OS that the 8gb limitation didn't apply: you lie to the BIOS and as long as what you boot (the actually code you load and jump to from the BIOS) was within that "fake" geometry, it would work.

Not always, it depends what the actual problem is, but IIRC my sister's laptop had this problem when I upgraded her to a 20gb disk and put XP on it.