Win2K reboots instead of shut down

I have a brand new computer with Windows 2000 O/S installed. It worked fine until I installed a Adaptec 2940 SCSI card with an external CD burner. Now when I go to “Shut Down”, the computer goes through normal shut down BUT instead of turning off itRe-Boots. I have to hit the power button before it reboots to turn off. Anybody ever heard of this or have a solution as to how to fix, short of removing the SCSI card.