Subject CachedRowSet problem

I'm thinking about moving away from the old JBuilder DataExpress.
CachedRowSet looks promising and I have done some test but ran across an issue.

I have two tables. PRODUCT and CATEGORY.
These tables have same name of the primary key.

When I want to update a row in the PRODUCT table after a join select of the two tables I get

org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -204
Ambiguous field name between table PRODUCT and table CATEGORY

I tried cachedRowSet.setTableName("PRODUCT") but it did not help?

Any friendly soul out there who has a workaround for this problem?