When I try to create a revision for a large node structure.

Umbraco.Courier.Core.Exceptions.PackageException: Unable to load item with id 'f0bfd541-e2e8-497e-b3c9-f651eb8f839a' from provider 'Documents' ---> Umbraco.Courier.Core.Exceptions.RetrieveException: Error retrieving item [f0bfd541-e2e8-497e-b3c9-f651eb8f839a] from provider [d8e6ad83-e73a-11df-9492-0800200c9a66]. ---> NHibernate.HibernateException: Found shared references to a collection: Umbraco.Courier.Persistence.V4.NHibernate.EntityClasses.UmbracoNode.ChildUmbracoNodes at NHibernate.Engine.Collections.ProcessReachableCollection(IPersistentCollection collection, CollectionType type, Object entity, ISessionImplementor session) at NHibernate.Event.Default.FlushVisitor.ProcessCollection(Object collection, CollectionType type) at NHibernate.Event.Default.AbstractVisitor.ProcessEntityPropertyValues(Object[] values, IType[] types) at NHibernate.Event.Default.AbstractFlushingEventListener.FlushEntities(FlushEvent event) at NHibernate.Event.Default.AbstractFlushingEventListener.FlushEverythingToExecutions(FlushEvent event) at NHibernate.Event.Default.DefaultAutoFlushEventListener.OnAutoFlush(AutoFlushEvent event) at NHibernate.Impl.SessionImpl.AutoFlushIfRequired(ISet`1 querySpaces) at NHibernate.Impl.SessionImpl.List(IQueryExpression queryExpression, QueryParameters queryParameters, IList results) at NHibernate.Impl.AbstractSessionImpl.List(IQueryExpression queryExpression, QueryParameters parameters) at NHibernate.Impl.ExpressionQueryImpl.List() at NHibernate.Linq.NhQueryProvider.ExecuteQuery(NhLinqExpression nhLinqExpression, IQuery query, NhLinqExpression nhQuery) at NHibernate.Linq.NhQueryProvider.Execute[TResult](Expression expression) at System.Linq.Queryable.Count[TSource](IQueryable`1 source) at Umbraco.Courier.Persistence.V4.NHibernate.Helpers.RelationHelper.HasRelations(ItemIdentifier relationItemId, String[] allowedTypes, ISession session) in c:\Program Files (x86)\teamcity\buildAgent\work\872c402d3442319c\Core\Umbraco.Courier.Persistence.NHibernate\Helpers\RelationHelper.cs:line 28 at Umbraco.Courier.Persistence.V4.NHibernate.Persisters.DocumentItem.RetrieveItem[T](ItemIdentifier itemId) in c:\Program Files (x86)\teamcity\buildAgent\work\872c402d3442319c\Core\Umbraco.Courier.Persistence.NHibernate\Persisters\Document.cs:line 134 at Umbraco.Courier.Core.ItemCrudProvider.RetrieveItem[T](ItemIdentifier itemId) --- End of inner exception stack trace --- at Umbraco.Courier.Core.ItemCrudProvider.RetrieveItem[T](ItemIdentifier itemId) at Umbraco.Courier.ItemProviders.DocumentItemProvider.HandlePack(ItemIdentifier id) in c:\Program Files (x86)\teamcity\buildAgent\work\872c402d3442319c\Core\Umbraco.Courier.Providers\ItemProviders\ContentItemProvider.cs:line 79 at Umbraco.Courier.Core.ItemProvider.Package(ItemIdentifier id) at Umbraco.Courier.RepositoryProviders.Local.Package(ItemIdentifier itemId) in c:\Program Files (x86)\teamcity\buildAgent\work\872c402d3442319c\Contrib\Providers\Umbraco.Courier.RepositoryProviders\Local\Local.cs:line 227 at Umbraco.Courier.Core.Packaging.RevisionPackaging.ƒ(ItemIdentifier itemId, ItemProvider provider, QueuedItemIdentifier itemInQueue) --- End of inner exception stack trace --- at Umbraco.Courier.Core.Packaging.RevisionPackaging.ƒ(ItemIdentifier itemId, ItemProvider provider, QueuedItemIdentifier itemInQueue) at Umbraco.Courier.Core.Packaging.RevisionPackaging.˜() at Umbraco.Courier.Core.Packaging.RevisionPackaging.Package() at Umbraco.Courier.Core.TaskManager.(IRevisionTask value) 1/11/2013 12:01:48 PM

What do I do?