Using the print screen key does copy the screen, but has bizarre results when I paste it into a paint program. If the file is still playing, the copied image will also move in the image editor. Even saving the file while the movie is paused doesn't work.
this whole thing has to do with overlays. overlays can't be captured in a normal fashion and i'm not aware of other ways... short of getting a program that allows it.
i have an old riva tnt that allows overlays to be turned off which allows printscreen to work, but newer cards don't have this for some reason.
and i experienced the movie playing in mspaint when i did a printscreen once, rigsta... it was a trip, but then i just realized it had to something with the overlays and detecting where the play window was.