I recently started with a fresh installation of Subsonic and started scanning my media drives from scratch. It went for a while and got up to 32185 files and got stuck, it hung there for a few hours before I ended the service completely and restarted it. I started scanning again and it went up very quickly as expected for files it already knows about, but again it hit the same number 32185 and hung on scanning. This is definitely not all of my files and it continues to say scanning while displaying the loading animation. In previous versions of Subsonic it had no problem discovering all of my files.
UPDATE 9/1
I'm still having the problem, but the number has changed, so I suppose some progress has been made. I'm now stuck at 32392. I've noticed ffmpeg.exe is initiated by and working hard through this process, which is strange. It's as if files are being transcoded when they are only supposed to be indexed.