I have following question:
my CMP beans (both entity and session) are calling ejbStore after each business method, that has a havy overhead in performance, does anyone know how to prevent this?
You are not a single wrapping tansaction, so each method invocation takes place in it's own transaction. At the end of a transaction the contrainer stores each entity accessed in the transaction.
You can prevent this by putting the code in a session bean or by using a UserTransaction.