On Sun, Oct 24, 2010 at 7:45 PM, Bob Hutchinson <hutchlists@midwales.com> wrote:

I ran some trials using form_example from http://drupal.org/project/examples
I found that indeed I should not use drupal_render() inside theme functions,
drupal_render_children() works fine.

It's ok to use drupal_render on $form's sub-elements inside $form's theme function, however you can not use it on the $form array as it causes an infinite loop.