Ask on the hibernate forum :)
I have the same issue. I disabled validation for now.
Pete this isnt a hibernate issue, i think its a seam issue because the mapping is saved in a seam reverse engineering xml file but it doesnt pick up the mapping. why?. Please help!!
It is a hibernate issue. The reveng.xml is from Hibernate Tools, and it isn't used to store mappings either.
The answer is that hibernate-tools isn't perfect, and sometimes makes mistakes (like this) which you have to correct by hand. If you come across such a problem you need to (1) fix it in your app, (2) report it in the hibernate tools forum so they can add it to the mapping files which come with hibernate tools.
You can also ask about reveng.xml on the hibernate tools forum.