Are you running IIS webserver by any chance? I found this while searching, bug.php?id=28929, and it seems to indicate it's a problem with IIS and running PHP in a certain way.
I am not sure if this issue is directly related to PowerStore or not, it seems to be more of a PHP issue. If possible it would be worth trying a package like XAMPP (xampp.html) which bundles apache and PHP and makes it very easy to get up and running.
-justin