mixx and impress

From: gary hasty 
Ok, here's a strange little thing I'm trying to figure out.  Will have my
ubuntu notebook running a media event showing a presentation with imbedded
video via a projector and also need Mixx running on my notebook screen for
some music mixing.  Looks like if I'm running mixx in Auto DJ mode on one
screen the video stops displaying via the projector.  The slideshow still
works just no video or audio imbedded.  Some strange config I haven't found
yet?  If I quit Mixx, all works in impress