PHP4.01pl2 and interbase

PHP4.01pl2 is supposed to include Interbase support, I have installed it on my NT server and writen a test connection to my database as set out in the PHP manuels.. I have tested PHP in my IIS server and it works great, however when I try to make an interbase connection through php I get the dreaded: "Fatal error: Call to undefined function: ibase_connect() in C:\InetPub\wwwroot\php\php1.php on line 11" Is there somthing that I have to enable in php.ini that anyone here is aware of that I may have missed? I tried looking for documentation on what is enabled in the linux version of php and not in the NT version, but couldnt find anything there. Obviously its trying to do it, so I think my syntax etc are correct. I am using the php4isapi.dll as opposed to the php.exe Regards, Adam Williams Macpro Software