Exactly the same exception after you have changed this property? Sounds like you are maybe not using the configuration file you think you are.
I can't tell you what Jars are required without knowing which version of Hibernate you are using, though the Hibernate documentation can. Missing Jars cause NoClassDefFOund errors - are you getting any of those?
For Hibernate 3.6.1 you need all the jars in the lib/required folder of the distribution, plus hibernate itself.