I'm having a problem with Just Another Cross Sell in conjunction with the Modules Manager mod. I receive the following error:

[FONT="Courier New"]Fatal error: Call to undefined method yclass::init_template() in /zentest/admin/module_manager.php on line 14[/FONT]

This error occurs after a correct, working installation of modules manager AND after installing the cross-sell mod AND when I click on Admin > Tools > Modules Manager, which I try to do because I cannot see Admin > Configuration > Cross Sell.

What troubleshooting avenues should I pursue?

[FONT="Courier New"]SERVER INFO

Zen Cart 1.3.8a
Database Patch Level: 1.3.8
v1.3.8 [2008-03-26 19:21:46] (Version Update 1.3.7->1.3.8)
v1.3.7.1 [2008-01-04 09:17:14] (Fresh Installation)

Linux

PHP Version 5.2.5
Configuration File (php.ini) Path /usr/local/etc/php5/cgi
Loaded Configuration File /usr/local/etc/php5/cgi/php.ini
PHP API 20041225
PHP Extension 20060613

MySQL 5.0.45[/FONT]