Widescreen/ Fullscreen Recognition Problem
 

I have a movie on my computer, m4v file, that is giving me fits when I try to put it on DVD. It's widescreen, and plays correctly with Windows Media Player, but when I right-click and check the "Properties," it's showing 640x478, which is full-screen. When I open it in Corel VideostudioPro, to put it on a DVD, it insists on making the DVD full-screen, which of course is distorted (everybody is tall and skinny), even though I have all the settings set to widescreen. I even tried rendering it as MPEG-2, 16:9 aspect ratio, before trying to put in on the DVD, and all it did was put black bars on the side, the video is still rendered as full-screen. Is there any way to correct this? The only thing I did to the original movie file that I bought was to eliminate the DRM using Requiem, which supposedly only strips the DRM without affecting the video quality. Any help is greatly appreciated. Thanks.