diff -upr ubercart/uc_cart/uc_cart.module ./uc_cart/uc_cart.module
--- ubercart/uc_cart/uc_cart.module	2010-08-11 10:09:54.000000000 -0500
+++ ./uc_cart/uc_cart.module	2011-02-01 15:32:10.515667002 -0600
@@ -268,6 +268,12 @@ function uc_cart_init() {
   $conf['i18n_variables'][] = 'uc_msg_order_logged_in';
   $conf['i18n_variables'][] = 'uc_msg_order_new_user';
   $conf['i18n_variables'][] = 'uc_msg_order_submit';
+
+  // Don't cache any cart of checkout pages.
+  // Code based on CacheExclude - http://drupal.org/project/cacheexclude
+  if (drupal_match_path($_GET['q'], 'cart/*')) {
+    $GLOBALS['conf']['cache'] = 0;
+  }
 }
 
 /**
@@ -290,24 +296,6 @@ function uc_cart_cron() {
 }
 
 /**
- * Implementation of hook_exit().
- *
- * Code from CacheExclude - http://drupal.org/project/cacheexclude
- */
-function uc_cart_exit() {
-  global $base_root;
-
-  $pages = array('cart', 'cart/checkout', 'cart/checkout/review', 'cart/checkout/complete');
-  $this_page = request_uri();
-  foreach ($pages as $page) {
-    if ($page && strstr($this_page, $page) !== FALSE) {
-      cache_clear_all($base_root . $this_page, 'cache_page');
-      return;
-    }
-  }
-}
-
-/**
  * Implementation of hook_nodeapi().
  */
 function uc_cart_nodeapi(&$node, $op, $arg3, $arg4) {