I am working with a Matrox SD widescreen sequence in PPro, which is 720x486 at 1.21 PAR. I need to export MPEG2 to a playout server for air. In Media Encoder, I use the NTSC DV preset, but then I get a very strange problem: If I try to change the default frame height of 480 to 486 (which matches the sequence), the frame rate options are limited to 23.976, 24 and 25. When at the default height of 480 (which softens the video), I have all the frame rates available and I can select the proper 29.97 fps. Ahyone know why this is?