I don’t know if its caused by itunes 7 or nighty svn-1376. I installed both at the same time.
But now, if I ad new songs to the music-directory and press rescan in the webinterface a reconect in iTunes is necessary before I see the new songs. Before they apeare immediatly.
There is a correct way to do updates, but I don’t do it right (Imagine that!) and it was causing playlist update problems. If you aren’t affected by it, you can change the “enable_updates” config value in the daap section of the web config to “yes”, and it should work the way it used to.