include_path

I'm new with php. I've installed apache 1.27, php 4.2.2 with windows 2000 and I'm trying to realize a web site. The include_path setting is: ".;C:/xxx/yyy/includes/others;C:/xxx/yyy/includes/myfiles" I get authentication.php in my include path and, unfortunatly, an other authentication.php does exist in the 2° path and is processed before my authentication.php file, and maybe gets a function name like one of mine. When, in a file I write: include("authentication.php"), my file is never included; php includes the first one that finds. What can I do to resolve this problem? Thanks. John M.