I can't believe I never noticed this till today, but it seems Quicktime X hasn't been uploading to youtube properly. HD files uploaded via Quicktime X max out at 480p on youtube. Meanwhle uploading the same file via youtube.com uploads to 720p. Has this been a Quicktime X bug since day one, or is this something new? I've now learned to make sure to double check my videos after uploading grrrrr.