I have a DW1655 and if you set it to burn +R as -Rom it will play in all players providing the disc is of reasonable quality. Some of the dyes they use in cheap discs just don't reflect as well. Also +R duals are the only dual layer discs in production and avaialable right now. I see you used some Memorex DL which have a less than stellar quality rating among The DVD burner crowd, SL seem to be OK. Most say only Verbatim has quality +R dual layer discs. I would recommend you try a disc scan in Nero CD-DVD Speed and see what the quality scores are. Most of my Memorex DL come in at 30 - 50 range and any Verbatims I have seen come in at 90+. You could always just use SL discs and try cutting out the menus and extras, most movies can be reduced to about 60-80% and still look good on the big screens.
I am waiting for the Lightscribe to come out on DL. I love making the labels.
