I use VLC media player (
http://www.videolan.org/vlc/) when I need a quick screenshot. Play the DVD, pause at the point you want the screenshot, then on the menu go to
Video >
Snapshot. You'll find the picture in your
My Pictures folder as
vlcsnap-xxxxx.png. You can change the destination directory and the image format to .jpg in the
Settings >
Preferences... menu. No need to mess with video acceleration, video overlays, and such.