All good suggestions. Yes, use i386 version not AMD64 unless you have a very good reason (no it will not give you noticably more performance). Why are you using the DL disk? Just use the single layer one, again unless there is a good reason.
SATA DVD drives have been known to have issues booting from DVDs, occasionally it is just the cable... people have had this issue several times with IDE drives. And, of course, the drive itself could have an issue - if you have a spare it is worthwhile eliminating that possibility.
When you download the image, always use the torrent not the straight mirror download, as this will ensure there are no corruptions. When burning the disk, note that DVD-R's are more compatible with drives that DVD+R's, and RWs/RAMs are beyond the pale! But most importantly of all, it is critical that you burn at the slowest possible speed the drive supports. This will ensure there are no corruptions during the burn. The nature of the 'canned' DVD install is that it is a very large, monolithic tar file, which makes it particularly vulnerable even to small corruptions.
Finally, do make sure you are actually burning the .iso file as a DVD image, and you haven't just burned the .iso file itself to the DVD. The latter will not work, the image has to be expanded into a DVD then burned by your burning software. The contents of the DVD should be lots of files and folders. If all you see is a .iso file, then you haven't burned it correctly.