Session dispose exception

[letarak]

DO 7.0 Sorry, can not reproduce in test environment Catch this exception three times

System.ArgumentNullException: Value cannot be null. (Parameter 'node')
   at System.Collections.Generic.LinkedList`1.ValidateNode(LinkedListNode`1 node)
   at Xtensive.Collections.TopDeque`2.PopBottom() in /_/Orm/Xtensive.Orm/Collections/TopDeque.cs:line 180
   at Xtensive.Caching.LruCache`2.Clear() in /_/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs:line 159
   at Xtensive.Orm.Session.DisposeImpl(Boolean isAsync) in /_/Orm/Xtensive.Orm/Orm/Session.cs:line 661
   at Xtensive.Orm.Session.Dispose() in /_/Orm/Xtensive.Orm/Orm/Session.cs:line 614

System.InvalidOperationException: The LinkedList node does not belong to current LinkedList.
   at System.Collections.Generic.LinkedList`1.ValidateNode(LinkedListNode`1 node)
   at Xtensive.Collections.TopDeque`2.PopBottom() in /_/Orm/Xtensive.Orm/Collections/TopDeque.cs:line 180
   at Xtensive.Caching.LruCache`2.Clear() in /_/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs:line 159
   at Xtensive.Orm.Session.DisposeImpl(Boolean isAsync) in /_/Orm/Xtensive.Orm/Orm/Session.cs:line 661
   at Xtensive.Orm.Session.Dispose() in /_/Orm/Xtensive.Orm/Orm/Session.cs:line 614