Incremental synchronisation failing for Microsoft AD connector when username has mixed case

2013-11-15 19:17:18,727 scheduler_Worker-2 INFO [atlassian.crowd.directory.DbCachingRemoteChangeOperations] Could not remove user [nabyndoor] from group [Pacnet Managed Services - All]. User was not found.
com.atlassian.crowd.exception.UserNotFoundException: User <nabyndoor> does not exist
        at com.atlassian.crowd.dao.user.UserDAOHibernate.findByName(UserDAOHibernate.java:66)
        at com.atlassian.crowd.dao.user.UserDAOHibernate.findByName(UserDAOHibernate.java:49)
        at com.atlassian.crowd.directory.AbstractInternalDirectory.findUserByName(AbstractInternalDirectory.java:141)
        at com.atlassian.crowd.directory.AbstractInternalDirectory.removeUserFromGroup(AbstractInternalDirectory.java:748)
        at com.atlassian.crowd.directory.DbCachingRemoteChangeOperations.removeUserMembershipsForGroup(DbCachingRemoteChangeOperations.java:702)
        at sun.reflect.GeneratedMethodAccessor257.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
        at com.atlassian.crowd.directory.$Proxy205.removeUserMembershipsForGroup(Unknown Source)
        at com.atlassian.crowd.directory.DirectoryCacheImplUsingChangeOperations.syncUserMembersForGroup(DirectoryCacheImplUsingChangeOperations.java:119)
        at com.atlassian.crowd.directory.ldap.cache.AbstractCacheRefresher.synchroniseMemberships(AbstractCacheRefresher.java:145)
        at com.atlassian.crowd.directory.ldap.cache.UsnChangedCacheRefresher.synchroniseGroupChanges(UsnChangedCacheRefresher.java:258)
        at com.atlassian.crowd.directory.ldap.cache.UsnChangedCacheRefresher.synchroniseChanges(UsnChangedCacheRefresher.java:81)
        at com.atlassian.crowd.directory.DbCachingRemoteDirectory.synchroniseCache(DbCachingRemoteDirectory.java:612)
        at com.atlassian.crowd.manager.directory.DirectorySynchroniserImpl.synchronise(DirectorySynchroniserImpl.java:63)
        at com.atlassian.crowd.directory.DbCachingDirectoryPoller.pollChanges(DbCachingDirectoryPoller.java:50)
        at com.atlassian.crowd.manager.directory.monitor.poller.DirectoryPollerJobBean.executeInternal(DirectoryPollerJobBean.java:29)
        at org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:113)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:203)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)