Same problem, copy plays well on all of my computers but not on my SONY DVP-NS 700P DVD player.
Then Clonedvd worked and your Sony dvd player doesn't like the Verbatim media that you bought. Try Taiyo Yuden Premium 8x dvd+rs and change the booktype to "dvd-rom". The other solution is to buy a standalone dvd player that does like the Verbatim blank media you bought.
I'm beginning to believe that Clone DVD is not producing an actual "clone" of the original.
No. That has no bearing whatsoever with your issue.
The original plays fine but none of the copies play.
No. They play in your computer. They just don't play in your Sony dvd player. Your Sony player doesn't like the Verbatim blank media that you bought obviously. Try something else or try a different player. Those are your options. This is a compatibility issue. Period.
While I'm the one who recommended Verbatim in the stickies, keep in mind that doesn't mean all Verbatim blank media will play on all standalone dvd players. Verbatim just happens to sell pretty good blank media, on average, that works well. The same goes for the other blank media I recommended.
If it turns out that I need a new more powerful computer and a new and more powerful burner it'll have to wait
No. That has nothing to do with this issue. Again, your Sony dvd player doesn't like the blank media you bought. The solution involves either finding blank media it does like (and Taiyo Yuden Premium booktyped to "dvd-rom" usually works for most standalone dvd players; you could also try Verbatim +R booktyped to "dvd-rom", but I am of the opinion Taiyo Yuden Premium silvers have a
slightly higher reflectivity, and thus read better across more players) or getting a standalone dvd player that likes your Verbatim blank media. Your choice . . . . choose an option.
You mentioned you will try Verbatim +Rs.
Ensure you're changing to booktype to "dvd-rom". Read
step 3