How to find where class is used?

In a large application that I am tasked with maintaining (vBulletin) there is a particular class that is used: vB_ProfileBlock_VisitorMessaging. I know the file that it is defined in, but I cannot find the file that actually creates a vB_ProfileBlock_VisitorMessaging object. I tried the brute-force grep approach, but the only place where I see the class mentioned is in the class declaration itself: [dev@localhost forum]$ grep -ir "vB_ProfileBlock_VisitorMessaging" * includes/class_profileblock.php:class vB_ProfileBlock_VisitorMessaging extends vB_ProfileBlock I know that this class is used as there is a page that is obviously using it. I have tried playing be-the-PHP-parser with that file, but it goes on to include() about a dozen other files, each of which include() another dozen files! This server does not and cannot have a debugger. What else can I do to find where this class object is created? Thanks. -- Dotan Cohen http://gibberish.co.il http://what-is-what.com