Hi all ! I got a problem with setting or sound card, i don't know yet what is it. But basically i got lexicon alpha sound card usb with pair of studio monitors Tannoy's. they are connect via USB to my macbook pro. they play sound and they stop and again the same thing with films music on ituens etc etc. But in logic for example message appears that there is an error with sample rates. But how to fix it? any idea ? i tried to reset computer, i tried to change sound settings for internal speakers, and also i tired turn off the audio core via task manager. But when i plug my monitors to iMac every things its fine, so from this i know its not the equipment but software or settings. PLEASE HELP.