Hard drive not detect

Recently purchased a new WD6401AALS 640 GB hard drive.Loaded win 7 64bit with no problems. The problems started on the first boot, in the boot up screen the mother board would not auto detect the hard drive, reboot and everything works fine. If I shut down the computer completely and start again the hd will not auto detect until I reboot the system. I have changed ports, sata cable and power supply connection but no luck. The WD6401AALS is set as the only boot device in the bios. I had a Seagate 250 GB hard drive with Winxp and no problems. While changing the hard drives I didn’t make any changes in the bios so the setting should work for both hard drives …no? I contacted W/D support and they more or less said to rma, just thought I’d give you good people a try before I went with the rma. Thanks

Very good, thanks, rma it is.