Excellent. One of the common errors is when the plugin (loadmodule) code is very different from the Application Server code.
So, locate the "conf" directory for your web server, and specifically, the "httpd.conf" file.
At the bottom of this file, locate the "WebSpherePluginConfig" directive.
This provides the fully qualified path to the plugin-cfg.xml file processed by the plugin load module.
Open this file using a text editor, and locate the "Log" directive (the first line that start with "<Log" This line should contain a "Name" attribute" that identifies the fully qualified path to the plugin log file.
Close this file, and open the plugin log file, and locate the lines that have:
... PLUGIN: Bld version
... PLUGIN: Bld date:
What version of the Plugin code is being used?