I have found that when saving a new song it sometimes gets automatically added to a song list and sometimes I have to do a rebuild.

I get the feeling it is related to the size of the song list. For short lists the new song gets added automatically, but for long lists it doesn't.

Is there a limit? If so, what is it? Can it be changed/removed? It would be nice if saving a new song always automatically added it to the song list rather than having to do a rebuild.