I have switch the header to alternative this way
<?php include (TEMPLATEPATH . '/header-blog.php'); ?>
and the post names are not showing up in browser title.
I left the header-blog.php file the same as header.php
When I switch back to classic header.php, it works.
It seems that file header-blog.php is not recognized as a header, and the header.php file is loading some extra function maybe.
Anybody has an ideas what could be the problem?