Rich Text custom field doesn't render on Activity form when Used For = Activities + Any type

Rich text custom field works ok on Activity form IF Used For = Activities + a specific activity type. But if Used For = Activities + Any, only the label is displayed - no input field.

Reproduced on demo and my local 3.2.3 sandbox.

Forum post: http://forum.civicrm.org/index.php/topic,15706.0.html