Is this a feature or a bug? Pictures that are already in the storyboard cannot moved in a (later inserted) snippet. The only way I found is to delete the pics and afterwards insert all again from source into placeholder of snippet.
I have the same problem. Also it seems that anytime I drop a pic that is not exactly on the correct spot on the snippet, the snippet appears to break up and the only workaround I have found is to delete the snippet and its pics and start over.