--- adserve.inc.orig	2009-03-18 10:19:13.000000000 -0700
+++ adserve.inc	2009-03-18 10:19:25.000000000 -0700
@@ -295,6 +295,9 @@
 function adserve_variable($variable, $value = NULL) {
   global $conf;
   static $variables = NULL, $overridden = NULL, $cache_loaded = array();
+  if ($variables === NULL) {
+  	$variables = new stdClass();
+  }
 
   // Update the value, if set.
   if (isset($value)) {