Index: template.php
===================================================================
RCS file: /cvs/drupal-contrib/contributions/themes/zen/template.php,v
retrieving revision 1.45.2.6
diff -u -p -r1.45.2.6 template.php
--- template.php	24 Jun 2010 03:40:16 -0000	1.45.2.6
+++ template.php	26 Jun 2010 19:04:07 -0000
@@ -571,7 +571,8 @@ function zen_preprocess_views_view(&$var
  *   The name of the template being rendered.
  */
 function zen_process(&$vars, $hook) {
-  if (array_key_exists('classes_array', $vars)) {
+  // Don't clobber Views 3 classes.
+  if (array_key_exists('classes_array', $vars) && !array_key_exists('classes', $vars)) {
     $vars['classes'] = implode(' ', $vars['classes_array']);
   }
 }