I have the same mobo, and it booted from CD by default.
Make sure you are using the Intel 6gb connectors, they are the gray ones on that mobo. In the Bios, set the priority to the cd/dvd first, then hard drive. If this isn't working, make sure you're in advance mode, click on the boot tab, and go down to Boot Override, and select your DVD drive. This should force it to boot from that device regardless of your other settings. Sometimes you also have to hit spacebar to make it boot from CD, otherwise it may time out and try to boot from the hard drive.