Odd Problem w/Linksys PCI Card

I'm a fair troubleshooter, but this one has me stumped.

I set up the Linksys WRT54G router on my XP Pro machine w/o a problem. I
loaded the drivers on my wife's '98 SE machine and installed the wireless
PCI card. Now, the machine hangs at the plug&play portion of startup or it
won't even wake the monitor and does nothing*. I tried all but one of the
four PCI slots (one is blocked by the AGP VC fan). I've played around with
IRQ's, I've checked all the BIOS settings, nothing helps. How can you tell
if the card is DOA?

* What's even stranger is that this machine had an Ultra 66 controller card
installed just prior to the above. I uninstalled the card and physically
removed it, changing the HDD connection to the MB. Without this card the
machine will not wake the monitor. When I put it back in it makes it to the
PnP phase before hanging. Take out both cards or just the wireless card and
the machine runs fine.

I've brought the sledgehammer upstairs, and I may have to use it!!


Lee