S/PIDF I/O Set-up issue

I'm trying to use the Aux In, S/PIDF Left & Right inputs. The MBox2Pro light shows that I am getting a signal. The I/O of the two tracks I'm using are assigned to S/PIDF Left & Right--one Left and one Right. The problem is that I'm not getting a signal on the actual tracks.



I/O Setup issue?



Please help, thank you.



MBox2Pro, iMac OS x 10.5.8