--- template.php
+++ template.php
@@ -23,7 +23,7 @@ function omega_preprocess(&$vars, $hook) {
 
   // If there is a base theme, collect the names of all themes that may have 
   // preprocess files to load.
-  if($theme_info->base_theme) {
+  if(!empty($theme_info->base_theme)) {
     global $base_theme_info;
     foreach($base_theme_info as $base){
       $themes_active[] = $base->name;