I'm running Vegas 7 and Vegas 9. I have no problem with either but in Version 9 if I start a new project and drop a clip into the timeline the preview window seems disabled and if you click anywhere on the clip nothing shows in preview.
I eventually got it to run as normal but I can't remember what I did to enable live preview!!! If I load an existing project everything runs fine!!
Does anyone know why the preview is disabled when you start a new project??? It has to be something that is not being initialised????