OK, I've isolated the issue. Again, I've placed one of the form fields in a LOAD wrapper. The POST action for the form does send a value for this field (according to Firebug), but web2py doesn't receive a value for it. Printing the form.error that is thrown results in this:
<Storage {'author': 'no data'}>
So the question is why the field value within the component isn't being
passed along. My hunch is that this is due to the LOAD helper wrapping the
select widget in an extra <div>.
