It seems the the forum messed up a bit with my XML. The CDATA sections *are* correct, the forums stripped the preceding <! and the following >.
But the rest seems to be correct. So, who knows how to help me? :)
You can't use LIKE with input parameters in EJB-QL. You may be able to override this in the jboss specific query, but I'm not sure since I never use them and didn't try it. If you want an exact match (which I think you do) just use the = operator instead of LIKE.
Strange it may be, but I have LIKE in other queries and JBoss don't complain about them. Strange... I think I'll update JBoss to the newest tip so I can use the new EJB-QL compiler.