Manik, Thanks for posting the JIRA. However, at the risk of appear to be a nit-picker, I don't think JBCACHE-1493 captures the extent of the problem as it pertains to R_R, and Hibernate - JBC3 interaction. Specifically, given an application that uses Hibernate and JBC3 (MVCC) as 2nd level cache in Transactional (as opposed to read-only) mode: 1. the pattern I described in the post linked below is not an edge case: http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217616#... Basically, this will take place whenever app logic is such that the 1st time a collection is accessed the intent is to alter it. 2. as far as I can tell, enabling writeSkewCheck will merely result in data version exceptions being thrown in this use case - making collection un-cacheable if app does a write on 1st access. Given the above pattern, and sequence of calls that HIbernate Core issues in case of Collections I think the solution is not to use pfer() in org.hibernate.cache.jbc2.collection.TransactionalAccess.putFromLoad() if R_R is in use. -nikita View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4218771#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...