Network drives, IIS, and PHP

Hey people. Despite exhaustive searching of the list archives, I am still stuck as to how PHP scripts may be called if they do not reside on a local drive. Using IIS, if I place a php file on a local drive, set up a virtual directory, and access it from a browser, everything works fine. However, if I place a file on a network drive and follow the same procedure, i receive an error like this: "Warning: Failed opening '\\Greerson\gsole\webpages\public\phpinfo.php' for inclusion (include_path='') in Unknown on line 0" I'm not that familiar with IIS permissions, but it must be something really simple. Any simple solution? Thanks in advance. (and please copy all replies to me as i'm only on the digest) Gareth Sole