I am trying to make a simple animation using the Export to SWF function in Illustrator CS3. I'm using the option that saves each layer as a frame in the animation. I set the crop area to 640w x 480h so I can then take the resulting SWF file and edit it into a larger video using another application. I drew a light blue rectangle larger than the crop area as a background for each layer. On a couple of the layers I accidently made the blue rectangle larger than on some of the other layers, but I figured that wouldn't matter since it was supposed to get clipped off. The rectangle covers the crop area in every frame.
When I select "Clip to Crop Area" in the SWF Options during the export, it creates an animation with everything working as expected except on the frames where the blue rectangle is larger, the image grows bigger to include the whole blue rectangle. It seems to be cropping to the largest artwork instead. As a test, I put a couple of small black rectangles completely outside the crop area, but within the blue rectangle, but they never showed up. As another test, on one frame, I made the blue rectangle have a thick red border. The border shows up in that one fram although it is completely outside the crop area.
So the question is, why does the outside edge of an object which spans the whole crop area (and then some) show up in the final SWF when I have selected clip to crop area?