I have Sugar 4.5 running on Windows 2003 with MSSQL 2005 and PHP 5.1

I am having trouble adding that module to the Accounts and Contacts Detail View, I get the following error:
Fatal error: ACLController::require_once() [function.require]: Failed opening required '' (include_path='.;C:\php5\pear') in C:\Inetpub\wwwroot\SugarCRMSQL\modules\ACL\ACLCont roller.php on line 189

Any help would be much appreciated.