now, we found some problems in cglib that prevent us using it as hibernate byte code provider.
We even recently sent them 2 patches of major issues and still cannot get them to apply the changes upstream and cut releases.
--------- cglib issues we found ------------
1. ClassEmitter does not preserve field annotations
cglib issue:
http://sourceforge.net/tracker/index.php?func=detail&aid=2796998&group_id=56933&atid=482368
hibernate issues:
http://opensource.atlassian.com/projects/hibernate/browse/HHH-4703 (https://jira.jboss.org/jira/browse/JBPAPP-3284)

test cases:
a) http://opensource.atlassian.com/projects/hibernate/secure/attachment/14912/minimal-test-cglib.zip
b) see patch1

2. java.lang.SecurityException: class
"mypackage.ExtCode$$FastClassByCGLIB$$7599b706"'s
signer information does not match signer information of
other classes in the same package.

cglib issue:
http://sourceforge.net/tracker/?func=detail&aid=947049&group_id=56933&atid=482368

hibernate issue:
https://jira.jboss.org/jira/browse/JBPAPP-2971

test cases:
there is no public test case can be used to reproduce this issue, we use https://anonsvn.jboss.org/repos/hibernate/sandbox/trunk/lobtest-ee5 in EAP 5 to identify this issue.
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