Index: modules/update/update.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/update/update.install,v
retrieving revision 1.3
diff -u -p -u -p -r1.3 update.install
--- modules/update/update.install	10 Oct 2007 11:39:34 -0000	1.3
+++ modules/update/update.install	30 Jan 2008 21:49:38 -0000
@@ -7,6 +7,8 @@
 function update_install() {
   // Create cache table.
   drupal_install_schema('update');
+  // Remove stale variables from update_status 5.x contrib, if any.
+  _update_remove_update_status_variables();
 }
 
 /**
@@ -38,3 +40,25 @@ function update_schema() {
   return $schema;
 }
 
+/**
+ * Private helper to clear out stale variables from update_status 5.x contrib. 
+ *
+ * @see update_install()
+ * @see update_update_6000()
+ */
+function _update_remove_update_status_variables() {
+  variable_del('update_status_settings');
+  variable_del('update_status_notify_emails');
+  variable_del('update_status_check_frequency');
+  variable_del('update_status_notification_threshold');
+  variable_del('update_status_last');
+  variable_del('update_status_fetch_url');
+}
+
+/**
+ * Clear out stale variables from update_status.
+ */
+function update_update_6000() {
+  _update_remove_update_status_variables();
+  return array();
+}