Well I'll be...

It was a freakin' setting in the MyDVD program!!!

In the application preferences under "Disc Recording", you can choose between "Faster disc finishing" (default) or "Enhanced player compatibility".

Silly me! When I installed the program, I wanted my DVDs to have maximum compatibility, so I had changed it Enhanced player compatibility!

When I realized that the CD Speed test wrote to a disk that I was having problems with in the MyDVD program, I got to lookin' at the preferences (and there aren't that many). The only preference that could've possibly been an issue was the one I changed. So I changed it back, and now my burner is recording +R DVDs that are playing on my TV right now!!!

So, I am very happy that this issue is resolved!!!

Thanks again Ssseth for your help and attention in dealing with this matter! You led me down the path that helped me realize that it had to be a software issue.