I figured out the problem.
As I noted earlier, when I run the app from within RAD on the local test server, it runs fine.
But when I export the ear (the export succeeds), and then deploy it on local server, it seems like it can't find the utility classes needed by the ejb module...
So, I made some changed on how the WebSphere loads the classes...
For my app, I changed "Class Loading and update detection"
For class loader order > Classes loaded with application class loader first
For WAR class loader policy > Single class loader for application
Once I made these changes, the app was able to find the classes, and the app runs fine now...
_Esam.