For some reason is one of my en_US.php files not being read by the system.
The thing is that i used to have this in the _config file for this "module": require_once( dirname( __FILE__ ) . '/lang/en_US.php' );
When having that it works. However, having it in 2.4 makes that en_US.php file the "master" file and no other "lang" files are read.
When i remove the require_once all is well except for this one en_US.php file that is not read.
I had to put the lang folder and file one folder up in the tree to get it to work