moleslayer,
The PCI compatability issue is one I've fallen foul of myself, and I highlighted it in a post about 6 months ago.
It isn't at all obvious - for the vast majority, PCI is PCI and it's only in the very fine print that the differences are noted.
I've put a link into the FAQ sticky - "Thinking of adding a PCI card to your old(ish) PC?"
SD