OM Layer, sequence problem with TDK1.1a11

[Herv� Guidetti]

Hi all, 
I use TDK1.1a11. I have a problem with the OM Layer. I have an object Person
in the DB (Postgres) using sequence. When I try to create a new person,
BasePeer returns an exception :
java.sql.SQLException: ERROR:  Relation 'null' does not exist.

I had a look into BasePeer :
 
    id = dbMap.getIDBroker()
     .getNextSequenceId(tableMap.getPrimaryKeyMethodInfo());
 
In fact, tableMap.getPrimaryKeyMethodInfo() returns null.
 
Is that a known bug ?
Do I miss something ?
 
Thanks for your help.
Herv�