Since it's at least trying to play the DVD+R, I'd say it's a problem with the quality of the media, the quality of the burner, the burning speed, or any combination of them.
I'd suggest trying different media brands, different burning speeds, and if all else fails a different burner.
Taiko Yuden, Ridata, Fuji are some manufacturers of media that are regarded as being very high quality. You need to be aware that most media on store shelves is rebranded, so the manufactuer of the media may not be listed on the label. For example, Officemax sells Fuji media as Officemax brand, OfficeDepot sells Ridata media as it's brand, at least until they decide to switch manufacturers that they purchase from. Personnally, I've had the best results from Fuji media.
Some brands of media (such as TDK) have special scratch resistant coatings on the disks. This is a great idea in theory, but can cause problems when used with some combinations of burners and readers.
The media is only one part. Not all DVD burners are created equally, and in the rush for speedy burners some manufacturers have let burning quality slip. I highly recommend Pioneer and NEC burners.
Some players have trouble with variable bitrates. So, you might try making sure the bitrate that your using is set as constant instead of variable and see if it makes a difference.
And lastly it may help if you can update the firmware of your burner to expand it's media compatability.
It would be nice if every manufacturer of media, players, and burners would get on the same quality level, and same standards. Alas, the world we live in is a far cry from a perfect world.
