You could try reseating/reinserting the card in the Mediator slot or changing the order of PCI cards in the Mediator. It shouldn't matter but it sometimes does.
You might check that you have the latest pci.library but I doubt there is anything wrong with it. The pci.library won't open if it doesn't find anything interesting. I have had it fail to open as well with Mediator and cards plugged in. My problem is on a warm 4000T after reboot so wouldn't help you. It does show how common poor grounding or old caps can cause problems though.