There is nothing wrong with defining static final variables inside entity beans. I doubt that this has anything to do with the problem you are experiencing.

The source of confusion some people may have about static variables inside EJBs is that you need to be careful when static variables are not final. This is because you don't always know how many classloaders have been used by the app server. Thus, assigning a value to a static non final variable in one classloader will not affect the other classloader for the same class. This can cause problems.