OK, this is the weirdest issue that I've come across. I have a Zotac 1050ti ITX that works when the video card is vertical (and the motherboard is horizontal). But when the computer is put vertical and the card is heatsink side down, the computer does not see the card. Other cards work in the system fine, so it is not the motherboard. Any ideas about what components I should be looking at that are wonky?