I'm not sure if this is a known issue or not, but the Youtube killer seems to not like the playlist view. Here's a quick example:
The same videos convert just fine when there's no list parameter in the URL.
If this is intentional (e.g. the playlist view doesn't work well with the HTML5 player), feel free to close – just wanted to write it down while I had a URL handy and hadn't forgotten yet.
Huh, thanks. That's because the first video in the playlist is not embeddable (a rare occurrence), and the YouTube killer for playlists doesn't work in that case. I can fix that. Still, the result will be a playlist with all entries but the first one grayed out.
You're totally right; it's just that playlist. I really should have checked a few others before I filed. Thanks for taking a look.
Fixed in 3.1.2.