Unable to get a EJB business object

I have a situation where I need to call methodB() of an EJB from methodA() of the same EJB, with a new transaction starting in methodB().

I read on some threads that getting a reference to the EJB through

sessionContext.getBusinessObject(EjbLocalInterface.class);

will work. But it gives me a

java.lang.Exception: com.ibm.ejs.container.UnknownLocalException: nested exception is: java.lang.IllegalStateException: Requested business interface not found.

I am currently working on EJB 2.1