Don,
It wasn't ad_form, but the stanadrd form builder procs. The validation worked fine.
The problem was, forums adds additional form fields on the confirm screen for attachements and notifications.
To get the validation checks into 4.6 without too much trouble I kept the form builder stuff that was already in there and added validation.
If there is a way to add validation to a form element after it is created, maybe I can try that.