FWIW, I had an almost identical issue with XPHD5.6.6 on XW8000 and LS4.1.5 on Ethernet, described in this thread: http://www.avid.com/exchange/forums/thread/237531.aspx Avid tech support was clueless, Jeff and Randall suggested a few things, their bottom line was 'abnormal behavior'. I moved along and started the new project using FC to avoid the issue