music download into GarageBand issue

Hi, All,

Stay with me on this one! I use GarageBand to compose and record songs, including a backing track so I can sing them live. I then put this backing track into iTunes on my desktop computer and from there into my iPhone to use on-stage. I then sometimes create another GarageBand song by downloading the backing track and recording a live vocal to see how it sounds. All works fine… until I modify the backing track and go through the same procedure. Then when I try to download the new version into a GarageBand song it’s the old discarded version that downloads not the new version. The new version is in the Music app on my iPhone, so the old one has been over-written, but it appears the old one is still embedded somewhere in the GarageBand software. Any suggestions?