Burnt DVDs were working on standalone player, but now won't

I have an unusual problem. I’ve read many posts regarding burnt DVDs not working on standalone DVD players, however my set-up has been working beautifully until the last week.

I use Intervideo WinDVD Creator 2 with Sony DVD-R to burn my animations and they used to played fine on my standalone Pioneer DVD player. All of a sudden this week they stopped working. I thought my DVD player was the problem, but the DVDs no longer work on my partners DVD player as well. I’m assuming I’ve unintentionally updated a codec or installed some software on my machine that is making things screwy. Does anyone have any suggestions?

have you exposed your dvd media to heat or anything of a magnetic structure. if so this could be your problem

does this only happen with burnt dvd’s or does the problem continue to occur with commercially bought dvd’s??

No one can help unless you provide some details.....