In a stateless session bean a transactional method only executes a simple query: "from " + xyz.class

the xyz.class has several relations and collections.

The problem is, that after the execution of the query a session flush tries to update one of the related objects (which leads to a StaleObjectStateEx)

There are only field access mappings (no side effects with setters).

It only occurs on a system with concurent writes.

It occurs on connection isolation level read_uncommited, but not on repeatable_read.

Is there an explanation for this beahaviour?

Could it be possible that hibernate read's an object twice from the database? The first time an older version , the second time after a concurrent process changed it, the new changed version?

hibernate version is 2.2.6

Thanks for any comments

Armin