Is there anyway you could use nvidia "nview" (the TV-out feature included on a number of geforce cards) to preview full screen to a monitor, much like you can if you "preview on external device" and route it out to your dv cam then rout the RCA outs to a monitor? Which is to say, when you have "nview" activated you can set it up to show any video that plays in media player or quicktime to automatically display full-screen on the composite outs. So i'm, assuming that because vegas uses direct x, the same would be possible for the video preview window.