SchemaAction='refresh,deleteTableContents' incorrectly removes data from ALL DB tables.

At my usecase not all tables are managed by openjpa so not all of them are listed with the class-tag inside persistence.xml. I set up openjpa to delete the table contents for developping with the following property:
<property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(SchemaAction='add,deleteTableContents')"/>

But now all contents are deleted even the one of tables which aren't listed inside persistence.xml.

Shouldn't openjpa only delete contents from tables which are configured plus the openjpa_sequence_table rather than deleting all contents from the whole database? Is this a bug or is there a property which I have to set to get the described behaviour?

Greets Oli