Top Navigation style broken
$_SESSION['s']['module'] wasn't changed yet in capp.php before nav.php was already called. Sometimes session data can get lost if you use redirects, and depending on the time capp.php will take the change of the session variable is done, or not yet before nav.php will request the data.
Adding a session_write_close() to capp.php will save the session data and nav.php will use the correct session data.
This was working correctly in the stable 3.0.3.3 release