ISAPI Interface

I'm writing an ISAPI interface for our web server to be used with PHP 4.xx When I request a PHP file, any php file, this is returned to the caller: Warning: Failed opening '' for inclusion (include_path='\winbbs') in Unknown on line 0 I know this is a zend error message, I just don't know what I'm doing wrong to cause it. Below is a debug dump of what was sent to the PHP ISAPI DLL. If nothing is shown after the - it contains an empty string. Could someone please look at this and tell me what I'm doing wrong. ============================================== EXTENSION_CONTROL_BLOCK cbSize - 144 dwVersion - 262144 ConnID - 0 dwHttpStatusCode - 200 lpszLogData - %s lpszMethod - GET lpszQueryString - lpszPathInfo - lpszPathTranslated - cbAvailable - 0 lpbData - lpszContentType - HTTP_COOKIE - UID="1DISK5259" HTTPS - off SCRIPT_NAME - 1941.php AUTH_PASSWORD - AUTH_TYPE - AUTH_USER - CONTENT_LENGTH - CONTENT_TYPE - PATH_TRANSLATED - \WINBBS\WORK\HTML\1941.php QUERY_STRING - REMOTE_ADDR - 216.106.46.93 REMOTE_HOST - www.webbbs.org REMOTE_USER - REQUEST_METHOD - GET SERVER_NAME - www.webbbs.org SERVER_PORT - 80 SERVER_PROTOCOL - HTTP/1.0 SERVER_SOFTWARE - WebBBS 1.30 APPL_MD_PATH - \WINBBS\WORK\HTML\1941.php APPL_PHYSICAL_PATH - \WINBBS\WORK\HTML\1941.php INSTANCE_ID - SetLastError(ERROR_NO_DATA) RETURN(FALSE) INSTANCE_META_PATH - SetLastError(ERROR_NO_DATA) RETURN(FALSE) LOGON_USER - SetLastError(ERROR_NO_DATA) RETURN(FALSE) REQUEST_URI - GET http://www.webbbs.org/1941.php HTTP/1.0 URL - /1941.php HSE_REQ_MAP_URL_TO_PATH_EX - \WINBBS\WORK\HTML\1941.php dwFlags - HSE_URL_FLAGS_SCRIPT cchMatchingPath - 27 cchMatchingURL - 27 lpdwSize - 27 --- WebBBS Secure Internet Information Server v1.30.3 : Genesis ( http://www.webbbs.org/ ) Log on to www.webbbs.org for free web based and pop3 [ virus free and spam free ] email accounts. Free access to virus and internet security message boards with 10's of thousands of new messages every month.