Interesting. If I change

$form['class'][$vid] = array('#type' => 'value', '#value' => $rev->class);

to

$form['class'][$vid] = array('#value' => $rev->class);

Then the problem goes away. I doubt I have uncovered a FormsAPI bug, so is this something that needs improved docs somewhere?

Nancy E. Wichmann, PMP
Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.