u46 mk2 on mac, problem

Hi,
I use my u46 mk2 with DVS and this morning, when I plugged my u46 on my macbook pro, Cross recognizes it but he does not recognize entry 3/4 and i have no sound.
DO you have any ideas ?
Thank you
I use my u46 mk2 with DVS and this morning, when I plugged my u46 on my macbook pro, Cross recognizes it but he does not recognize entry 3/4 and i have no sound.
DO you have any ideas ?
Thank you