I have an .mkv file I want to burn to a DVD - but whenever I try and import it into iDVD nothing happens - either iDVD freezes or it doesn't become imported. I assume that means it doesn't support .mkv? If so, what's the best way for me to convert it to something iDVD will recognize with no to little quality loss? The file is HD and I'd like it to stay HD. Thanks!