New Build - Connecting I/O Panel to Mobo

Hey guys, i just got my new rig running and everything is going smoothly. I have a Cooler Master RC-690 and EVGA nForce 750i FTW mobo, for some reason i can't get the usb ports/headphone/microphone jack on the top of my case functioning correctly. I followed the manual for my motherboard and found the internal headers to plug in the respective wires coming from my case into the mobo, but for some reason they still aren't being detected. I made sure i plugged everything in the right place, there seems to be a simple detection problem though. I'm not sure if i'm being clear or not. Basically i want the external usb ports and sound jack on the front of my case (they happen to be on the top) working, and i'm pretty sure i plugged the wires into the right places on the motherboard. Any suggestions would be helpful, thanks guys.