Scan doesn't always find all files

[ses1984]

Version 5.0 (build 4100) – September 21, 2014
Server jetty-6.1.x, java 1.7.0_65, FreeBSD (90.8 MB / 119.5 MB)

I just installed subsonic for the first time and I've been playing with my media library.

At first I noticed that it only scanned less than half the files in my library. I manually re-scanned a few times and it always found exactly the same number of files.

I identified one album that was not scanning and I was trying to figure out why. The album was just regular V0 mp3 files with no particular special characters in the file names. It looked like this:

/media/music/Savant - Orakel V0/
/media/music/Savant - Orakel V0/Savant - Orakel - 01 Orakel.mp3
etc

I renamed this folder like so:

/media/music/orakel/
/media/music/orakel/Savant - Orakel - 01 Orakel.mp3

Then I manually re-scanned and suddenly subsonic found an extra 20,000 files. I think this all the files in my library but I'm not 100% sure.

Is there any way to try to troubleshoot what was happening before, so it doesn't happen again?

Thanks