--- subdomain.module.orig	2008-10-20 10:03:05.000000000 +0200
+++ subdomain.module	2008-10-20 10:06:38.000000000 +0200
@@ -117,7 +117,7 @@
  * Implementation of hook_user
  */
 function subdomain_user($op, &$edit, &$user_edit, $category = NULL) {
-  if ($op == 'validate' && variable_get('subdomain_type', SUBDOMAIN_USER) == SUBDOMAIN_USER) {
+  if ($op == 'validate' && isset($edit['name']) && variable_get('subdomain_type', SUBDOMAIN_USER) == SUBDOMAIN_USER) {
     // If configured, disallow username changes if subdomains are set to Node Authors
     if (is_numeric($user_edit->uid) && $user_edit->name != $edit['name']) {
       if (variable_get('subdomain_allowchange', SUBDOMAIN_ALLOWCHANGE_NO) ==  SUBDOMAIN_ALLOWCHANGE_NO
@@ -425,4 +425,4 @@
     $raw = str_replace(SUBDOMAIN_CUSTOM_TOKEN_ID, $id, $raw);
   }
   return subdomain_subdomain_to_token(subdomain_raw_to_subdomain($raw));
-}
\ No newline at end of file
+}