Hi Steve,
We are using Hibernate 3.5.5 GA, we are experiencing the similar issue which you mentioned fixed.

daemon prio=10 tid=0x00002aabe335bc00 nid=0x474f waiting for monitor entry [0x0000000056e93000..0x0000000056e95d90]
  java.lang.Thread.State: BLOCKED (on object monitor)
       at org.hibernate.util.SoftLimitMRUCache.get(SoftLimitMRUCache.java:74)
       - waiting to lock <0x00002aaaeb8cd6d8> (a org.hibernate.util.SoftLimitMRUCache)
       at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:92)
       at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
       at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
       at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1760)

But after 7 to 10 minutes this block got disappeared, no requests are getting processed between this blocked time.

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