I have a computer with built-in AGP video, but no AGP
slot. It also has an add-in PCI video card, and the AGP card
is not used. However, KNOPPIX always tries to use the AGP
card, so XFree86 fails. Using the "noagp" option does not help,
because it is still getting confused by the presence of more
than one video card. When it tries the VESA driver, X is able
to produce a low-res display, but it is reported as a failure,
and no X session is started.

SO, when multiple video cards are found, it would be good
to either find a way to probe for which one is 'in use', or
give a menu option to choose a video card.