Video Card detection issue.

[Deleted]

So, I've bought a second video card today in hopes to set up SLI but when I place both cards in my machine with the SLI bridge and their power, the device manager and Nvidia control panel only detect one of the two cards. I've tried both cards individually, I've tried both PCI-E slots and they both work fine. This has been puzzling me for a while and I can't seem to get it to work. I'm fairly certain both cards are receiving power because their stock fans are rotating.

My parts are as follows:
CPU - Intel i7 960 3.2GHz
GPUs - Palit GTX 550 Ti (http://www.palit.biz/palit/vgapro.php?id=1542)
Motherboard - MSI X58 Pro-E
RAM - 6gb
OS - Win7

All and any help is appreciated, thank you.

[baller1308]

How's your PSU wattage?

[Deleted]

How's your PSU wattage?

750W which I am 99.99% sure is more than enough for this setup.