Index: wp-includes/pluggable.php
===================================================================
--- wp-includes/pluggable.php	(revision 10455)
+++ wp-includes/pluggable.php	(working copy)
@@ -426,15 +426,10 @@
 
 	$user = apply_filters('authenticate', null, $username, $password);
 
-	if ( ($user == null ) ) {
-		// TODO slight hack to handle initial load of wp-login.php
-		if ( empty($username) && empty($password) && ($GLOBALS['pagenow'] == 'wp-login.php' ) ) {
-			$user = new WP_Error('',''); //No Error
-		} else {
+	if ( $user == null ) {
 		// TODO what should the error message be? (Or would these even happen?)
 		// Only needed if all authentication handlers fail to return anything.
 		$user = new WP_Error('authentication_failed', __('<strong>ERROR</strong>: Invalid username or incorrect password.'));
-		}
 	}
 
 	if (is_wp_error($user)) {
Index: wp-includes/user.php
===================================================================
--- wp-includes/user.php	(revision 10455)
+++ wp-includes/user.php	(working copy)
@@ -50,8 +50,13 @@
 
 	$user = wp_authenticate($credentials['user_login'], $credentials['user_password']);
 
-	if ( is_wp_error($user) )
+	if ( is_wp_error($user) ) {
+		if ( $user->get_error_codes() == array('empty_username', 'empty_password') ) {
+			$user = new WP_Error('', '');
+		}
+
 		return $user;
+	}
 
 	wp_set_auth_cookie($user->ID, $credentials['remember'], $secure_cookie);
 	do_action('wp_login', $credentials['user_login']);
@@ -66,11 +71,6 @@
 function wp_authenticate_username_password($user, $username, $password) {
 	if ( is_a($user, 'WP_User') ) { return $user; }
 
-	// TODO slight hack to handle initial load of wp-login.php
-	if ( (empty($username) && empty($password)) && $GLOBALS['pagenow'] == 'wp-login.php' ) {
-		return $user;
-	}
-
 	if ( empty($username) || empty($password) ) {
 		$error = new WP_Error();