When I flatten an acroform, the radio buttons no longer show as checked.

If I don't call flatten (CFPDF....flatten="true"), the PDF shows the radio buttons selected, but as soon as I flatten the PDF, the radio buttons are not shown as selected. Checkboxes work, text fields work, but radio buttons just all show as unselected.

This is on CF 9,0,1,274733. Has any one else seen this?

Any suggestions?