Summary: rel=author requires full URL, Profile field that supplies this info requires only the Google+ ID for its link
After doing a bunch of troubleshooting, it appears that the Google+ field used for the Author Profile requires only the user ID (in my case +Clint.DeBoer) and this is the field also used for the Author Social link to Google+.
That means that for the Author social box, the URL is automatically rewritten to prepend "http://plus.google.com/" but this prepend is NOT added to the top rel="author" URL which is very important for Google authorship.
As a result, the top rel="author" is rendered as:
<link rel="author" href="http://+ClintDeBoer"/>
If I fix the field to correct the rel="author" then the lower Google+ icon link in the Author Bio is incorrect.
How might I work around this, and can this be fixed in a subsequent update?