The reason it isn't plugged in all the way is because the thing where the graphics card screws in is too high for it to connect to the motherboard, but it does click with the 2.0 slot. I am wondering if the problem is that there are 8 pins from the power supply, but only 4 pins for the motherboard. Could that be a problem also?
600W power supply.
NZXT Phantom 410 Case
AMD Phenom II
Geforce 520 2GB
Motherboard: Honestly couldn't tell you
I can go find it but it'd take a couple of minutes.