I did the reverse build, so it loads sansa first. I also added a new folder called songs, since the music folder is hidden. Now when I add songs it will refresh in the sansa firmware, but not in rockboxes. Because of this I can't put on any new songs. I read the sansafaq and it didn't help me.
I went to database settings and did initialize now and update now and those did not help.
Update: I retried the initialize and update database and it worked, I don't know why it didn't work the first time.