#014360: problems with $imap->top() command in gmail

i connected via imap to the gmail imap server which works.
i can get the messages with $imap->listMessage();

$messages = $imap->listMessages();
foreach ( $messages as $messageNr => $size )
  {
      $this->imap->top( $messageNr );

      $set = new ezcMailVariableSet( $imap->top( $messageNr ) );
     $mail = $parser->parseMail( $set );
      $mail = $mail[0];
      echo "From: {$mail->from}, Subject: {$mail->subject}, Size: {$size}\n";

  }

calling $imap->top( $messageNr ) results in an endless load

Operating System: mac osx 10.5.6
PHP Version: 5.2.6
Database and version: mysql 5.0.41
Browser (and version): Firefox 3.0.5

1) connect to gmail with imap and option ssl=true
2) get message list
3) get headers with top() command -> endless loading