Dynex and a Memorex are not exactly high quality media to start with, try to get some Verbatime.
It could also be his DVD player, some are very picky what to play.
If DVD+R, book type to DVD-Rom. DVD-R usualy work fine.
Try to burn at 1/2 rated media burning speed.

You get what you paid for. When I look for media, I try to find some made in Japan. It has been shown that the best dye plants are in Japan. If you can't find any like that, buy the Sony Accucore 16x from Walmart or something. They are selling a 50 pack spindle for $22. I have a OLD DVD standalone player, JVC 10 years old or more, that was real picky about discs but it loves these Sony Accucores.

First off, some standalone players tend to be a little picky about the media you feed them.

I've actually found that the cheaper players seem more widely accepting of a variety of blank media.

Booktyping +R format discs to DVD-ROM can certainly help some of the more picky players accept the media.

The brand or dye of the blank media is also a bigger factor than most newbies tend to believe. These guys have already posted about that, and they're right. There is no substitute for good quality blank media.

Thanks for the advice to all. I have been slammed at work but will head out to get different blanks today and give it a try.