[PHP] Windows 2000 Permissions error

[King, Justin]

While trying to use dir() on a certain directory, I get the error 
 
"Warning: OpenDir: Invalid argument (errno 22) in
c:\inetpub\wwwroot\search\update.php on line 71".
 
I'm aware this is most likely a permissions error, but I've already
given SYSTEM, SELF, and SERVICE full control over the directory.  I have
to restrict access to a few users on our network for this directory so
EVERYONE isn't an option.
 
Anyone have any ideas as to what I need to set the permissions to?
 
-Justin