Vegas applies the project's Pixel Aspect Ratio to the frame when saving the image. If you're using NTSC DV then the PAR is 0.9091. 220 x 0.9091 = 200.002. The resulting still will have a PAR of 1.0, so it's still the same size and shape as the video frame. This is done because *most* photo editing software assumes a PAR of 1.0.