While looking for a solution to my problem I saw someone posted an identical problem back last summer where no one replied. The error is caused by not declaring the fields in your key class to be public. The error shows up in the log similar to this
java.sql.SQLException: Unexpected token: ) in statement [CREATE TABLE PROCESSEJB (id VARCHAR(256), state VARCHAR(256), type VARCHAR(256), CONSTRAINT PK_PROCESSEJB PRIMARY KEY ())]
The specification requires the use of public I believe and it all makes sense after you figure out what you forgot to do but, it can be pretty frustrating for someone learning J2EE like myself to track down the cause. Hope this helps someone in the future.