jacorb.properties contains the following comments, which appears to be no longer true in EAP 5. To change the logging level you need to alter the priority of the Log4J category "jacorb.config". In addition, the default Log4J settings allow the warning to be printed by default, when previously it was not printed due to the log verbosity setting.

1. controls log output (to the console!) during the configuration stage.
2. This can help to find out which config files are actually loaded!
3. 0 : nothing is logged
4. 1,2 : only errors
5. 3,4 : info (which config files were loaded)
   jacorb.config.log.verbosity=0
6. If you set the property above to nonzero, the messages
   #
7. "jacorb.home unset! Will use '.'"
   #
8. and
   #
9. "File ./jacorb.properties for configuration jacorb not found"
   #
10. will appear at the console when the JBoss server starts. These messages
11. can be safely ignored.