New Graphics Card Won't Work!

Purchased an MSI Gtx 660 ti for my machine, which uses a Fujitsu D2990A-1 motherboard. Plugged everything into the required slots, but went I go to boot the PC it fails on the POST test with 5 beeps to indicate a Process Failure.

Motherboard specs are here ftp://ftp.ts.fujitsu.com/pub/Mainboard-OEM-Sales/Products/Mainboards/ClassicDesktop/D2990-A/Documentation/DS_D2990-A1.pdf

GPU - http://www.novatech.co.uk/products/components/nvidiageforcegraphicscards/nvidiagtx660tikeplerseries/n660ti-2gd5oc.html

I had been using integrated graphics, as it was enough to run XI at a reasonable level. I've disabled the drivers for that, and in the BIOS set it to PEG/PCI. Wired correctly to a 500 watt PSU, and without the GTX 660 ti in everything boots. Also placed a different graphics card in the PCI-E slot to test it, and everything has loaded fine.

Any tips?