I discovered today after upgrading and rebuilding some server hardware that Plex, Windows Media Server, and this new "Groove" thing won't play some of my FLAC files I ripped from CDs. These files weren't touched and other FLAC files on the same drive play fine.
Since the size seems fine, I tried playing in VLC - and they play fine! From the file dates, it seems like rips from only several days around 7/4/2011 have been affected. mp3tag also seems to see the embedded metadata (title, album art, comment with freedb id, etc) fine, but windows doesn't.
I used EAC back then (and actually probably still would for the few new CDs I buy). I could re-rip but my CDs are super-disorganized. Any ideas what could be wrong with these files?