If your Denon player is returnable, I would do that. If Upconversion to 720p or 1080i is what you want, in addition to DTS sound, I would change the player to, perhaps an Oppo or,
if you have a few dollars,
an HD-A1 HD DVD which not only does a wonderful job of Upconverting but, for HD DVD playback, gives you greater sound (even with DD Plus which your a/v will decode as DTS in a 1.5 Mbps bitrate).