jars are not loaded from the lib directory of a sar in JBoss AS 5

In JBoss AS 5, any jars placed in the lib directory of a sar are not loaded and results in a class not found exception. The classes are loaded if the jar is placed in the root directory of the sar.
On previous versions of JBoss AS, the classes would be loaded from either location. This prevents sars that would have worked on JBoss AS 4 to fail on JBoss AS 5.

Steps to reproduce:
1) take zip attached to this report.
2) deploy test-in-lib.sar to JBoss AS 5. The sar will not deploy and will fail with a classNotFoundException
3) deploy test-in-lib.sar to JBoss AS 4, the sar will deploy without issue.

test-in-root.sar will work on both versions of JBoss. The only difference between these sars is the location of the jar.