I'm using:

SlimServer Version: 6.5b1 - 9232 - Windows XP - EN - cp1252
Perl Version: v5.8.7 MSWin32-x86-multi-thread
MySQL Version: 5.0.22-community-nt (built-in version)
Music IP API Version: 1.7 (Build date: 8/25/2006)

I am currently relying on just Music IP to manage my library - I was getting duplicates and very slow scanning before so I have disabled "Use iTunes" and cleared out my library folder path in my SlimServer settings.

SlimServer is not reloading the Music IP library at the specified interval. In my SlimServer settings, I have my MusicMagic reload interval set for 3600 (I've also tried it at shorter and longer intervals with the same results). I added some new music to Music IP, analyzed, refreshed, and reloaded the cache in the API. 

Several hours have come and gone and SlimServer has not reloaded my library to reflect the new music.  I have tried refreshing my library via both the Music IP application and the API and SlimServer never automatically re-imports my library.  I turned on logging (d_scan, d_import, and d_musicmagic) but no log entries were ever created as though nothing were happening until I forced a manual scan of new and changed files, which updated my library properly.