sorry for this stupid question but
I don'n remember where I must put
the Primary Key Class for an Entity Bean
(with a compound PK): in the same package
of the Entity Bean Class, in the package
of the Entity Bean Interfaces or in any other
package I want ?
You can keep it in any package. You have to give the class name with complete package in your ejb-jar.xml. So it doesn't matter where you keep as long as it is within your jar file.