[Mediawiki-l] trying to use CategoryPageView hook, but getting an 'Article' Class not found error

Hi All, I'm trying to write a hook extension using CategoryPageView. We want the category page customized for certain categories. I'm using Jim Hu's SplitCategoryPage extension as sort of a model. However, when I include my extension I get a blank screen and when I check my logs I get the following error: [04-Mar-2008 09:22:40] PHP Fatal error: Class 'Article' not found in C:\wiki\includes\CategoryPage.php on line 15 Is there something I should consider about the order of includes? We're using: MW 1.9.2 PHP 5 MySQL 5 IIS (I know we need to upgrade, but we need to find all the places we have changed core code first.)