I am having trouble cropping a screen caputure from an NTSC DVD. when i crop it, it does not want to seem to crop the area i select. it crops the top and not the bottom. i am pasting the screen capture into a transparent RGB image, but all the RGB chans R showing up as black. I can c the image on the screen. Does this have something to do w/ some type of copy protection on the disc? how can i crop what i want?