ProcessInstanceInfo not getting updated when using JPA2

The test case is as follows:

1. The process starts, the transaction ends and in a second transaction just retrieves the process instance (which updates the lastReadDate on the process instance info).

This is what I figured out so far:

• if I'm running this in Hibernate4 with JPA1 (so JBPMorm.xml + ProcessInstanceInfo.hbm.xml) it works (I can see the update statement)
• if I run this in Hibernate4 with JPA2 (so JBPMorm-JPA2.xml) it doesn't work

So it seems the entity mapping in the JPA2 orm is not identical to the hibernate mapping it seems (or Hibernate doesn't treat them equal at least).