joomla - Fatal error: Call to a member function... adminpages/user.manager.php

In Joomla Administrator I click on Components/Gallery2/User Management. I select one of the users. I click on the radio button to add the user to the Site Admins group. After I click on "Save" I get the following error:

Fatal error: Call to a member function on a non-object in /home/.irving/vjrw/veronajrwrestling.org/administrator/components/com_gallery2/adminpages/user.manager.php on line 110

Any suggestions? I need to turn one of the users into a Site Admin.

Gallery version = 2.1.2 core 1.1.0.2
PHP version = 4.4.4 cgi
Webserver = Apache/1.3.37 (Unix) mod_throttle/3.1.2 DAV/1.0.3 mod_fastcgi/2.4.2 mod_gzip/1.3.26.1a PHP/4.4.4 mod_ssl/2.8.22 OpenSSL/0.9.7e
Database = mysql 5.0.24a-standard-log, lock.system=flock
Toolkits = ArchiveUpload, Exif, Getid3, NetPBM, Thumbnail, Gd, SquareThumb
Acceleration = none, none
Operating system = Linux mariposa 2.4.32-grsec+f6b+gr217+nfs+a32+fuse23+++opt+c6+gr2b-v6.192 #1 SMP Wed Dec 14 17:06:16 PST 2005 i686
Default theme = matrix
Locale = en_GB
Browser = Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0