How to get SPDIF inputs working?

[roubignolle]

Hello,
I have a MBP 13" 2.53 ghz, an MAUDIO Fast Track Ultra and PTMP 8.0.3. Everything works fine exept when I try to record through the SPDIF input of the FTU from a DAT TASCAM. The DAT works fine, I ve been using his SPDIF outputs for a very long time with an MBOX2.
In my I/O setup, the SPDIF goes to input 7 and 8. But when I try to record a track from input 7 or 8, nothing is getting recorded...
Do I miss something?

Thank you for your help!

edit : in the control panel of the FTU, the S/PDIF fader can't be moved, they are in grey and not in black...
edit 2 : by puting the clock to external, i can move the fader, but still, no sound...