I'm not sure if this is MySQL related or not, it occurs on the OpenSymphony Confluence instance trying to remove pages.

org.springframework.orm.hibernate.HibernateSystemException: Flush during cascade is dangerous - this might occur if an object was deleted and then re-saved by cascade (remove deleted object from associations); nested exception is:
net.sf.hibernate.HibernateException: Flush during cascade is dangerous - this might occur if an object was deleted and then re-saved by cascade (remove deleted object from associations)
net.sf.hibernate.HibernateException: Flush during cascade is dangerous - this might occur if an object was deleted and then re-saved by cascade (remove deleted object from associations)
at net.sf.hibernate.impl.SessionImpl.flush(SessionImpl.java:2174)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:711)
at net.sf.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:1319)
at net.sf.hibernate.engine.Cascades$4.cascade(Cascades.java:114)
at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:436)
at net.sf.hibernate.engine.Cascades.cascadeCollection(Cascades.java:526)
at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:452)
at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:503)
at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:482)
at net.sf.hibernate.impl.SessionImpl.preFlushEntities(SessionImpl.java:2583)
at net.sf.hibernate.impl.SessionImpl.flushEverything(SessionImpl.java:2190)
at net.sf.hibernate.impl.SessionImpl.flush(SessionImpl.java:2179)
at net.sf.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:61)
at org.springframework.orm.hibernate.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:309)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:218)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:172)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:196)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:135)
at $Proxy83.removeContentEntity(Unknown Source)
at com.atlassian.confluence.pages.actions.RemovePageAction.doRemove(RemovePageAction.java:45)