If that is your index file no wonder it doesnt work.
Usually there is a sendheader call a user authentication which calls their stylesheet and a threads call to $html= newhtml blah blah
If you want this to be apart from threads at the very least you need to specify a stylesheet link and to get the html to be correct you need to open and close everything correctly.
Something like this
<?
echo <<<PRINT
<html>
<title>
Test Sidebar
</title>
<head>
<link rel="stylesheet" href="http://www.yoursite.com/forum/stylesheets/default.css" type="text/css" />
</head>
<body>
PRINT;
require ("/home/wwwtsbiu/public_html/test/devboard/main.inc.php");
require ("/home/wwwtsbiu/public_html/test/devboard/pals/sidebarpal.php");
echo <<<PRINT
</body>
</html>
PRINT;
?>
Also as Josh stated the reauthenication is inside the sidebar script so you might want make a second copy called sidebarpal1.php or something like that and set the reauthentication inside their to 0.
