I've just realized: how is this possible ? The javax.sql.DataSource.getConnection() doesn't declare it can throw JBossResourceException !
I've debugged and I've noticed that, even if I see the JBossResouceException in the server logs, it's actually an SQLException that is thrown. Sorry for the msg, but it's a bit confusing when you see it (it logs a JBossResourceException, but throws an SQLException).
And the problem therefore is what?