I moved from 3.3.2 to 3.5.6 so I don't know when exactly this has been changed. In DerbyDialect there used to be the TableHiLoGenerator which is now commented out. When running on a DB that was created with SchemaGenerator from earlier releases the new Dialect gives ConstraintVialoations as the old ID columns are not of type identity. I could work around by sublassing DerbyDialect and implement the Genrator again.
Latest Derby, Core 3.5.6
DerbyDialect is deprecated by DB2Dialect. Is there still an issue there?