I was having doubled playlists in the latest nightly, so I chose to rescan and wipe cache.

 While the rescan was progressing, but after my playlists were loaded, I chose a playlist to play.  Pressed 
NOW PLAYING.  Scrolling through Now Playing playlist artist and album titles and track numbers were 
there, but song titles were missing, also missing in Song Info and web interface, even after those tracks 
were scanned.  Other tracks have full metadata.

Scan completed, titles still missing.

Cleared playlist.  Started a rescan (no wipe), completed.  Titles did not reappear in affected tracks.

Tried a rescan with wipe.  SlimServer crashed with: 

Can't call method "url" on an undefined value at /usr/local/slimserver//Slim/DataStores/DBI/
DBIStore.pm line 647.

Restarted.  Came back with 2 albums in the library.  Started a rescan with wipe.  Affected tracks are still 
missing titles.