This morning I decided to, once again, try my hand at converting our Mac Geek Gab podcast to AAC format. Normally it's done by someone else, but today there was a scheduling snafu so I figured I'd get it done. I set about doing this in GarageBand and all seemed fine. Fine, that is, until I exported my final version and found that though my chapters and images worked, my links would not appear.
I'll spare you the rest of the story and cut to what I've learned after three hours of lost time: GarageBand doesn't like ampersands for Enhanced podcasts. At all.
Apple acknowledges that ampersands are unacceptable for podcast chapters in Snow Leopard, but this little bug goes deeper than that. Regardless of the ampersand status of your chapters, if just one of your URLs (or URL titles) have an ampersand, NONE of the URLs or titles will appear or activate. Trust me, I did a LOT of tedious trial-and-error on this.
URLs that point to some database-driven sites will often have ampersands to delineate between multiple variables required to be passed in the request. In most cases, these ampersands are required in order to get to exactly the place you wish to visit. I used a service like bit.ly as a workaround. Just paste your ampersand-laden URL into bit.ly, and it will regurgitate an even shorter, ampersand-free version for you to embed in your show.
Happy enhanced podcasting!