just to add to this, i've noticed that,
for example I had an artist called
Blink-182, i had previously synced this with my device so the folders read
Blink-182 where appropriate.
However, recently i corrected this to
blink-182.
While the changes on the computer were fine to do with the case (all my music moved from
Blink-182 to
blink-182, on my device the music would stay in
Blink-182 and therefore ask me to re-sync all my blink-182 songs every time.
The work around i've just manually done, is to delete the
Blink-182 folder on my device and then re-sync to let musicbee recreate the folder with the correct case. I imagine this is more Windows' fault rather than MusicBee's