--- includes/css.inc	2010-02-09 04:37:11.000000000 +0800
+++ includes/css.fixed.inc	2010-04-11 20:18:03.315679861 +0900
@@ -238,7 +238,7 @@ function ctools_css_assemble($css_data) 
   // Iterate through all the statements.
   foreach ($css_data as $selector_str => $declaration) {
     // Add the selectors, separating them with commas and line feeds.
-    $css .= strpos($selector_str, ',') === FALSE ? $selector_str : preg_replace(", ", ",\n", $selector_str);
+    $css .= strpos($selector_str, ',') === FALSE ? $selector_str : str_replace(", ", ",\n", $selector_str);
     // Add the opening curly brace.
     $css .= " {\n";
     // Iterate through all the declarations.