Appointment reminder blank page

when click on appointment reminder i get blank page
here is the error from /var/log/httpd/error_log

[Thu Mar 22 12:16:57 2012] [error] [client 2.90.170.248] PHP Fatal
error: Call to undefined function areminder_fsrnav() in
/var/www/html/admin/modules/areminder/page.areminder.php on line 0,
referer: http://my_ip_address/admin/config.php

running

[[email protected] ~]# php -ver
PHP 5.3.10 (cli) (built: Feb 3 2012 09:06:11)
Copyright © 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright © 1998-2012 Zend Technologies
with Zend Guard Loader v3.3, Copyright © 1998-2010, by Zend Technologies

fedora 11
asterisk 1.6.2.23

I GET THE SAME ERROR WITH
centos6
asterisk 1.8.5

thx and cheers