Garageband 10 songs won't show in iMovie Content Library
After upgrading both Garageband and iMovie to version 10 I find that Garageband songs do not show in the iMovie library. I get the error message "19 files are missing iLife preview and unavailable". Files created using version 9 of Garageband do show up OK but having upgraded my songs to Version 10 I can no longer open them in Version 9.
Does anyone know what the issue is and whether I have something set up incorrectly?
iMac (21.5-inch, Late 2013), OS X Mavericks (10.9)