Index: t3lib/class.t3lib_beuserauth.php
===================================================================
--- t3lib/class.t3lib_beuserauth.php	(revision 7623)
+++ t3lib/class.t3lib_beuserauth.php	(working copy)
@@ -346,7 +346,7 @@
 				}
 				if ($warn)	{
 					t3lib_utility_Mail::mail($GLOBALS['TYPO3_CONF_VARS']['BE']['warning_email_addr'],
-						$prefix.' '.$subject,
+						'=?utf-8?b?'.base64_encode($prefix.' '.$subject).'=?=',
 						$msg,
 						$this->notifyHeader
 					);
@@ -356,7 +356,7 @@
 				// If An email should be sent to the current user, do that:
 			if ($this->uc['emailMeAtLogin'] && strstr($this->user['email'],'@'))	{
 				t3lib_utility_Mail::mail($this->user['email'],
-					$subject,
+					'=?utf-8?b?'.base64_encode($subject).'=?=',
 					$msg,
 					$this->notifyHeader
 				);