Windows video not working with projector but powerpoint slideshow does work

When I connect my Inspiron 6000 to my Epson lcd projector, I can see my computer desktop icons and the PowerPoint slideshow will work with dual monitors.  However, when I try to run windows video (.wmv) through the projector it only works when I toggle to select the projector as the only monitor.  I need to be able to see the video from both the laptop as well as on the screen.  Does anyone have any clues for me?

 

This happened for no apparent reason after almost a year of working smoothly with NO PROBLEMS.  I use this feature weekly, and it is giving me a real headache!  I use windows movie files within my PowerPoint slideshows and all of a sudden I can't do it without having to toggle the monitors to get the vid to work.  I have tried lowering screen resolution and have really up my whole dual monitor settings trying to get it back.  Can someone please help?

 

Thanks a bunch!