Problem with Sata ports on Dell inspiron 531s

Hi all I have a Dell Inspiron 531s motherboard ASUS M2N61-AX and my problem is I can only get 2 of the Sata ports to work. I'm trying to plug in 2 hard drives and a Dvd drive. If I plug in the hard drives to Sata 0 and 1 they will work but the DVD drive will not. If I plug in the DVD drive into Sata 0 and a hard drive into Sata 1 it works but the other hard drive won't. The BIOS isn't recognizing anything in SATA 2 or 3. Also the sata cables I'm using all work.

Thanks any help is appreciated.