What on earth is wrong with this thing?!?!

This is one WEIRD problem... hope someone out there has a better idea here of what's wrong than I do.

On my 2nd rig, sometimes when I power it up it will give me 4 BIOS beeps and do absolutely nothing from there but run the case fans. I jostle the video card around a bit and then it's fine. It's not a big problem as long as I have the side off on this thing but I want to put it back on soon, and I don't want to have to take it off everytime the video card needs a bump. Could this be a mobo problem, video card problem, driver problem... or something else???

It sounds like you already got it figured out! 4 beeps means "no vide card detected" and since it works again after you jiggle it, it would seem that you need to find a way to more securely install the card. Perhaps also the slot it fits in may have a defect, but I bet you just need to screw the card down real tight.

one long and 3 short usually is the video card not seated right or bad