Index: modules/overlay/overlay-parent.js
===================================================================
RCS file: /cvs/drupal/drupal/modules/overlay/overlay-parent.js,v
retrieving revision 1.40
diff -r1.40 overlay-parent.js
783c783,785
<           var fragmentizedDestination = $.param.fragment(self.getPath(window.location), { overlay: params.destination });
---
>           var prefix = Drupal.settings.overlay.cleanURLs?"":"%3Fq%3D";
>           var fragmentizedDestination = $.param.fragment(self.getPath(window.location), { overlay: (prefix+params.destination) });
> 
Index: modules/overlay/overlay.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/overlay/overlay.module,v
retrieving revision 1.17
diff -r1.17 overlay.module
502a503
>   drupal_add_js(array('overlay' => array('cleanURLs' => (variable_get('clean_url', FALSE) == TRUE))), 'setting');