That's because there are more players on the market that can read the -R format, though now all players can read both -R and +R and have been able to for several years. I have burned hundreds of DVD+R DL discs and have yet to have a problem with any of them, though I also only use high-quality Verbatim media for DVD+R DL. Using Memorex or some of the off-brands that are known to be highly unstable with poor dye layers means creating a disc with a very limited lifespan.
I have found very many DVD players have no trouble with DVD+R DL burned discs, but there are some that refuse to load them. One of my friend's Sony players from 2001 refuses to play the DVD+R DL discs I send him, but his Sony player from 2005 plays them just fine. One would have to go back to pre-2000 to find DVD players that have trouble/can't play DVD-R discs, though the dye layer has a lot to do with whether players can focus in on it and play it. There are some DVD-R brands and DVD players that are just poor when it comes to compatibility. One of my players will usually not recognize discs burnt onto Ritek media (which I stopped using years ago anyway), though at one time it would read them.
There are a lot of variables when it comes to using burned media, period. I should think that if Warner chose for a few special titles to be dual layer they would actually make a small pressed run of them in that format due to the compatibility issues with dual layer media with players out there on the market.
Quote:
Originally Posted by
smithb 
They could use dual-layer disks. However, while I do not have a dual- layer burner I had heard from a few people that they were more problematic. Maybe that is no longer an issue but if so, it may be why they have stayed away from them. Also, they are more expensive, but for what they are charging that shouldn't be an issue.
Personally, I would stay away from +R's and stick with -R's. While I can burn both I had issues early on with some DVD players reading +R's but very rarely an issue with a -R.