i did resolve the problem . I had to lunch the Motu in the garbage !!!
I m now using a old MidiMan Syncman that convert SMPTE to MTC then the MTC goes in a Saffire LE so now Pixel Mad recognize the TC .
I strongly raccomand to do NOT use MOTU XT or AV . those things are @+"><£ ... you know what I mean .
Also I think if richard could make a SMPTE READER module into the Cat / PM / SaMsc control pannel , where those use the LINE IN to get SMPTE things will be more easy .
thanks