I've found following thing.
If I have Two ears and in both I have a class A with static field B (for example constant) both EARs use the one and the same field of the Class A in both EARs. This means that if I want to deploy two application that uses different versions of the library with different constants I'm not sure which constants will be used because Jboss will init the first accessed static fields of class A.
I think this is a bug because EARs should not share their static classes to another ones. For example in resin with different wars this problem does not occure.
It's not a bug.
You need to isolate your ears with a <loader-repository> tag if you do not want to share class definitions.