Index: wp-includes/user.php
===================================================================
--- wp-includes/user.php (revision 11300)
+++ wp-includes/user.php (working copy)
@@ -85,7 +85,7 @@
$userdata = get_userdatabylogin($username);
- if ( !$userdata || ($userdata->user_login != $username) ) {
+ if ( !$userdata ) {
return new WP_Error('invalid_username', sprintf(__('ERROR: Invalid username. Lost your password?'), site_url('wp-login.php?action=lostpassword', 'login')));
}