Exporting Podcast issues

I have 120 third grade students creating podcasts with GarageBand '11. Whenever I share the podcast (Either 'Send Podcast to iTunes or "Export Podcast to Disk") the audio portion of the podcast is present, but never the graphics inserted on the podcast track. I've made attempts on several different machines without success. I am using the AAC encoder option. I've been able to export podcasts successfully with previous versions of GarageBand so this is very frustrating.

I would greatly appreciate instructions on how to export podcasts successfully!

Victoria