i think you need to re-read this guide. seems you didnt use the calculator. also if you rip with
dvdfab the movie will be compressed to fit a SL dvd. so just use all default settings for imgburn (expect 8x write speed). if you follow my video for dvdfab and imgburn you only have to change three settings in imgburn.
imgburn guide
http://forum.imgburn.com/index.php?showtopic=4632
dvdfab and imgburn video
http://youtube.com/watch?v=fsE5m62FcSE