MBox Mac connectivity problems

Cosmo

I have my MBox hooked up to my Mac.I'm running 2 stereo outs from my MASTER OUTPUT on my mixer, into the appropriate ins on the back of the MBox, the outs from the MBox to 2 ins on my mixer, and the USB cord into a dedicated port on the back of my Mac tower.However, I'm not getting a read on the computer. When I open up SYSTEM PREFERENCES to switch the input/output, and choose Digidesign HW from the list, the computer says "the selected device has no input/output controls." I know I'm getting a read from my source though, because I hear it in my headphones connected to the MBox.Any ideas why this isn't working? Thanks for any suggestions in advance.Confused in Crooklyn,King Caveman.

Jonny_Paycheck

Make sure that your sample rate is set to the same thing on all machines.