PHP (under httpd) reading a file outside DocumentRoot?

I don't know if this is an Apache (httpd) or a PHP issue (I suspect PHP, but I may be doing something wrong with mod_suexec), so I hope this is the right place to ask. I certainly appreciate any help anyone can offer! I am trying to get a PHP script to read a file that's outside the DocumentRoot of a VirtualHost, in fact well outside the parent directory of all of my virtual hosts. I have successfully managed to get Apache httpd to run the script as the correct user and group (matching the target file's ownership) using SuexecUserGroup. I tested this by having the script create/write a test file, which had owner and group set correctly. However, when I run the script, at the file("/path/to/target/file") command, PHP tells me it can't open the file - permission is denied. In php.ini safe_mode is off and open_basedir is not set. I am not sure where else to look for a solution - any help is very much appreciated! FYI: PHP 5.2.6, Apache httpd 2.2.11, mod_ssl/2.2.11, OpenSSL/0.9.7l on Mac OS/X 10.5.5. I'm reaching the script over an SSL (https) connection if that matters). Thanks!