I still don't know why EJB_3 must know anything about the persistence units that don't belong to it.
Anyway, I fixed this by adding a persistence.xml file to the ear. I get a "resource already registered" error at deployment, but things work fine.
This is getting annoying.
Why does JBoss follows an alphabetic order when doing the deployment?
Shouldn't it follow the order given in "application.xml"? Now another bean called BeanB which depends on BeanK isn't being deployed.
BTW, BeanB calls BeanK, which has the PU_K. That's why it isn't being deployed. BeanB (for some reason) wants the PU_K registered, but until BeanK isn't deployed, the PU_K won't be accessible.
This is very frustrating. Three days to migrate from Jboss 4 to 5.
Hell, I just repeat the Persistence Unit declaration in every JAR and things start working... well, I get a zillion (PU_K is alredy registered), but it works.