I'm trying to build a very easy standalone program in order to use Hibernate 3.0.

I get the following message: "GeneradorIdPais.java": cannot access org.hibernate.engine.SessionImplementor,bad class file: C:\COMPONENTES\hibernate-3.0beta3\hibernate-3.0\hibernate3.jar\org\hibernate\engine\SessionImplementor.class,class file has wrong version 49.0, should be 48.0,Please remove or make sure it appears in the correct subdirectory of the classpath. at line 5, column 29

I suppose I'm using a JDK with a early version than JDK which hibernate was build.

What JDK was used in order to compile Hibernate 3.0?

Thanks in advanced.