M-Audio is currently investigating a reported issue of a possible incompatibility with the Firewire 410 receiving incoming digital clock signal from an external digital audio device while running the internal audio on internal sync clock instead of using the external clock source.

Workarounds:
Method 1:
Do not use internal sync clock for audio playback, leave the sync clock set to external and set the sync clock on the external master digital clock source. For example, setting the external digital clock sample rate to 44.1Khz for CD-Audio playback.

Method 2:
In the FireWire 410 Hardware Tab, please select the digital input connector that is not in use during playback of audio using internal sync clock. For example, if an optical cable is plugged into the FireWire 410, select Coaxial as the digital input in the SPDIF input selection.

If two digital cables are connected to both optical and coaxial, disconnect the least used cable and select that unused connector in the FireWire 410 Hardware Tab.

M-Audio is planning to resolve this issue with a future update to the driver.