DataAccessException when detecting duplicate memberships while synchronising

We are running Crowd for user management, and before we integrated with our organizations larger Active Directories it was working fine. As soon as we integrated with a single large directory the following error began faulting and it is rendering Crowd useless. No user group updates are being recognized, new users have to be created in each application in order to be granted access, etc.

The error below is thrown and causes the entire synchronize to be aborted. I am experiencing the exact behavior when doing a synchronize in Confluence as well (see my comments at https://jira.atlassian.com/browse/CONF-22631?focusedCommentId=264657#comment-264657):

2011-08-22 08:06:18,646 QuartzWorker-0 ERROR ServiceRunner [atlassian.crowd.directory.DbCachingDirectoryPoller] Error occurred while refreshing the cache for directory [ 10300 ].
com.atlassian.crowd.embedded.ofbiz.db.DataAccessException: org.ofbiz.core.entity.GenericEntityException: while inserting: [GenericEntity:Membership][id,223267][membershipType,GROUP_USER]lowerParentName,#abc dl-video ad escalation[parentId,50839][childId,36518][childName,karreece][lowerChildName,karreece][directoryId,10300]parentName,#ABC DL-Video Ad Escalation (SQL Exception while executing the following:INSERT INTO cwd_membership (ID, parent_id, child_id, membership_type, group_type, parent_name, lower_parent_name, child_name, lower_child_name, directory_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?) (Duplicate entry '50839-36518-GROUP_USER' for key 2))
at com.atlassian.crowd.embedded.ofbiz.db.OfBizHelper.createValue(OfBizHelper.java:167)
at com.atlassian.crowd.embedded.ofbiz.OfBizInternalMembershipDao.createMembership(OfBizInternalMembershipDao.java:112)
at com.atlassian.crowd.embedded.ofbiz.OfBizInternalMembershipDao.addUserToGroup(OfBizInternalMembershipDao.java:105)
at com.atlassian.crowd.embedded.ofbiz.OfBizDelegatingMembershipDao.addUserToGroup(OfBizDelegatingMembershipDao.java:71)
at com.atlassian.crowd.embedded.ofbiz.OfBizDelegatingMembershipDao.addAllUsersToGroup(OfBizDelegatingMembershipDao.java:44)
at com.atlassian.crowd.directory.CachingDirectory.addAllUsersToGroup(CachingDirectory.java:125)
at com.atlassian.crowd.directory.DbCachingRemoteDirectoryCache.syncUserMembershipsForGroup(DbCachingRemoteDirectoryCache.java:671)
at com.atlassian.crowd.directory.ldap.cache.AbstractCacheRefresher.synchroniseMembershipsForGroup(AbstractCacheRefresher.java:126)
at com.atlassian.crowd.directory.ldap.cache.AbstractCacheRefresher.synchroniseMemberships(AbstractCacheRefresher.java:63)
at com.atlassian.crowd.directory.ldap.cache.AbstractCacheRefresher.synchroniseAll(AbstractCacheRefresher.java:37)
at com.atlassian.crowd.directory.DbCachingRemoteDirectory.synchroniseCache(DbCachingRemoteDirectory.java:645)
at com.atlassian.crowd.manager.directory.DirectorySynchroniserHelperImpl.synchronise(DirectorySynchroniserHelperImpl.java:84)
at com.atlassian.crowd.manager.directory.DirectorySynchroniserImpl.synchronise(DirectorySynchroniserImpl.java:63)
at com.atlassian.crowd.directory.DbCachingDirectoryPoller.pollChanges(DbCachingDirectoryPoller.java:50)
at com.atlassian.crowd.manager.directory.monitor.poller.DirectoryPollerJob.execute(DirectoryPollerJob.java:34)
at org.quartz.core.JobRunShell.run(JobRunShell.java:195)
at com.atlassian.multitenant.quartz.MultiTenantThreadPool$MultiTenantRunnable.run(MultiTenantThreadPool.java:72)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)
Caused by: org.ofbiz.core.entity.GenericEntityException: while inserting: [GenericEntity:Membership][id,223267][membershipType,GROUP_USER]lowerParentName,#abc dl-video ad escalation[parentId,50839][childId,36518][childName,karreece][lowerChildName,karreece][directoryId,10300]parentName,#ABC DL-Video Ad Escalation (SQL Exception while executing the following:INSERT INTO cwd_membership (ID, parent_id, child_id, membership_type, group_type, parent_name, lower_parent_name, child_name, lower_child_name, directory_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?) (Duplicate entry '50839-36518-GROUP_USER' for key 2))
at org.ofbiz.core.entity.GenericDAO.singleInsert(GenericDAO.java:156)
at org.ofbiz.core.entity.GenericDAO.insert(GenericDAO.java:121)
at org.ofbiz.core.entity.GenericHelperDAO.create(GenericHelperDAO.java:63)
at org.ofbiz.core.entity.GenericDelegator.create(GenericDelegator.java:489)
at org.ofbiz.core.entity.GenericDelegator.create(GenericDelegator.java:469)
at org.ofbiz.core.entity.GenericValue.create(GenericValue.java:77)
at com.atlassian.crowd.embedded.ofbiz.db.OfBizHelper.createValue(OfBizHelper.java:162)
... 17 more