My Fireface UFX seems no longer to work (starting today) on my Mac Pro using FW800. After starting the UFX the FW Led lights blue as it should. When i send a signal to it (iTunes, Cubase, Wavelab, doesn't matter) the FW-LED starts blinking and the audio signal i stuttering. I did not change anything regarding my system configuration.

Firmware and drivers are the latest ones, i did the . Mac OSX is 10.7 Golden Master (since more than a week and until today the UFX worked fine).

USB is still working fine.

Any suggestions how i could diagnose the problem?