When using WMP Plugin in DO's Preview-Mode some MP3's won't be played. They still will play in WMP itself. Also this happens with some videos.
I use Win 7 x64 with K-Lite-Codec-Pack (latest).
You'll have to give us more to go on than that. What's different about the ones which do play vs the ones that don't?
First...sorry, meant active x plugin, on WMP Plugin files unfortunately don't play automatically.
No difference, it's like most files Lame 3.93, 192 kbps, ID 2.3. Also if I decode them to wave they won't play also.
I recently read a similar problem: an user has problems with his internal player, when trying to play wave files with a higher sample rate than ususally, like 48/24 or 96/24.