--- domain_prefix.admin.inc	2009-01-15 18:19:11.000000000 +0100
+++ domain_prefix.admin_new.inc	2009-01-15 18:19:29.000000000 +0100
@@ -357,7 +357,7 @@ function domain_prefix_form_submit($form
     // Throw away what we don't need.
     $prefix = domain_prefix_string($form_state['values']['domain_id']);
     $tables = $form_state['values']['table_data'];
-    $unset = array('prefix_theme', 'domain_id', 'op', 'submit', 'restore', 'form_token', 'form_id', 'form_build_id', 'execute', 'table_data');
+    $unset = array('prefix_theme', 'domain_id', 'op', 'submit', 'restore', 'form_token', 'form_id', 'form_build_id', 'execute', 'table_data', 'domain_arguments');
     $data = $form_state['values'];
     foreach ($unset as $key) {
       unset($data[$key]);