Where are you trying to access SessionFactory from?
I had the same problem when I was trying to access SessionFactory from my unit tests (in eclipse) .
if that's the case,
this is what i did (not sure if the best way to solve it or not):
include the jbossall-client.jar, your client.jar and ejb.jar as well as jboss-ejb3.jar, jboss-aop-jdk50-client.jar and jboss-aspect-jdk50-client.jar in the classpath of your unit tests/client and give it another try.
If you came up with a better solution please let me know.