For those continuing to experience audio glitches (and kernal panics) in FCP during playback via Matrox devices, their support team has posted a thread in the Matrox User Forum to collect system info, etc in an effort to fix the problem:
http://forum.matrox.com/mxo/viewtopic.php?t=6297
Cameron Clendaniel
film editor, NYC
http://www.camclendaniel.com