It'd be safe to note that the webserver runs as a privelaged user, and sometimes webhosts hide users in a virtual directory; sometimes it may LOOK like your home is in one directory when it is infact something differant.
You can snag the path through a phpinfo.php file:
Look for something similar to:
_SERVER["DOCUMENT_ROOT"] /var/www/html
That is the full path to your web root according to apache on the server, from here you can ultimately craft the proper directory to your members file.