One of my entites has a compound PK consisting of strings.  That might be the reason, I get a lot of exceptions like:
Accidentally left out String key support ... I just committed a fix for that.

Does excludeEntities really works or am I missing something else?
It appears that the shouldSynchronizeEntity method was no longer called after all the refactoring to support jgroups ... I just committed a fix for this also, so filters should be applied.