Unfortunately, I'm getting Orcale problems as well. Most of mine stem from Null pointers on user - which is clearly filled in. I'm trying nightly builds (I wish I knew enough to actually be able to go in and hack a bit..), so if my situation automagically resolves itself, I'll post it.
Did anyone figure out the null pointer exceptions?
do you really need to use the Oracle XA stuff? i figure you only really need it if you are doing true distributed transactions with some other XA database. i started down the oracle xa route about a year ago, kinda got it to work but then i tried the straight minerva stuff and found it was about 3 times as fast and transactionally sound in a single database environment (actually its oracle OPS, 2 instances, but we never really get transactional between the instances). like i said that was a year ago, since then the system has done hundreds of thousands of transactions with zero error.
I'd really appreciate it if all those who posted clearly indicated which JBoss version they are using. For anyone using JBoss 3 rc1, please consult http://main.jboss.org/forums/thread.jsp?forum=67&thread=13366 If there are further problems, please indicate what they are with a log excerpt and your db-service.xml and login-conf.xml files.
For the original question about 2.4.x, you can remove the ConnectionFactoryLoader mbean since you aren't using it for anything. It is not clear from your log excerpt that there is a problem nor what it might be. What exactly is going wrong? What do you expect? What are you (or maybe your code;-) doing?
For the question about whether xa is necessary -- I would expect xa might be at worst about 1/2 the speed of non-xa, since for a minimal db tx (start, one sql op, commit) you have 4 calls to the db (begin, op, end, commit) as opposed to 2 (op, commit) for non-xa. However, with local tx it is possible to get into situations where you can run out of connections if you use RequiresNew calls from Requires calls, and if you are doing complicated operations the concurrency on xa should be much better. However, I don't have actual experience with this, and if the driver is slower this could outweigh the theoretical advantages.