On a Dell Dimension 4500S, I disabled the Intel on-board video card and 
added an ATI Radeon 7500 (PCI). ddcprobe lists the Radeon, lspci shows both
cards.

redhat-config-xfree86 will not start, even if I tell it not to use the existing
configuration file, because rhpl.videocard.VideoCardInfo() returns the onboard
card (it only returns the first card in the list from kudzu):

>>> import rhpl.videocard
>>> videocard = rhpl.videocard.VideoCardInfo()
>>> print videocard
primary: 0
vidCards: [<rhpl.videocard.VideoCard instance at 0x81f878c>,
<rhpl.videocard.VideoCard instance at 0x82ce8cc>]
Primary Video Card Info:
device: None
descr : Intel Corp.|82845G/GL [Brookdale-G] Chipset Integrated Graphics Device
server: XFree86
cardManf: None
vidRam: 16384
carddata: {'CHIPSET': 'Intel 845', 'DRIVER': 'i810', 'NAME': 'Intel 845',
'NOCLOCKPROBE': ''}
devID: Intel 845
fbmodes: None
fbbpp: None

Kudzu output:

>>> import kudzu
>>> cards = kudzu.probe (kudzu.CLASS_VIDEO, kudzu.BUS_PCI | kudzu.BUS_SBUS,
kudzu.PROBE_ALL);
>>> print cards
[Desc:           Intel Corp.|82845G/GL [Brookdale-G] Chipset Integrated Graphics
Device
Driver:         Card:Intel 845
Device:         None
, Desc:           ATI|Radeon 7500 QW
Driver:         Card:ATI Radeon 7500
Device:         None

rhpl needs to either return the add-on card if there is a disabled onboard card
or return all cards found so the frontend program can ask the user which to
configure.