Maybe that was too much information. The bottom line is, the new version of JAXB doesn't seem to support inheritance correctly, and it doesn't seem to handle interfaces correctly ( or at least, not in the same manner that the prior version of jaxb did ).
I'm willing to rework my approach if I can find something else that will work. I need to define a list of objects of various types. The range of types is limited to a known set.
In our dtd (JAXB 0.21), it looked something like this:
<!ELEMENT ObjectList (AObject | BObject | CObject | DObject )* >
But so far, I'm having no luck duplicating this functionality in new JAXB.