PCI-E problems!

I've just got an ASROCK P4775Dual-Pro motherboard, and a gainward 6600gt, I got these to improve my performance ingame, I know theyre are not the best around but its all I could afford. I used to have the same but with a ati 9200 AGP card. The problem is is that the Nvidia card is PCI-E and supports x16 speed, which the motherboard also claims to support. Only problem is I cant get it running at that speed so its basically as slow as my old 9200. Anyone have any ideas on how to fix this? I've looked all over the bios and cant find anything, even updated the bios :(
Help!!!!

I seriously doubt whether having less than 16 PCIe lanes available to your video card is going to have any bearing on the performance problem. SLi on older NF4 boards runs with only 8 lanes for each card.

Something else is wrong if it seems slow...