one more BUG

Unexpected error: The given key was not present in the dictionary.
Details:
Microsoft.Mashup.Evaluator.Interface.ErrorException: The given key was not present in the dictionary. ---> System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. ---> System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
at System.ThrowHelper.ThrowKeyNotFoundException()
at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at Microsoft.Mashup.EngineHost.Services.StreamStorage.OpenStream(Int32 id)
at Microsoft.Mashup.EngineHost.Services.EncryptedPersistentCache.EncryptedStorage.OpenStream(Int32 id)
at Microsoft.Mashup.Common.PersistentCacheExtensions.TryGetValue(IPersistentCache cache, String key, Stream& stream)
at Microsoft.Mashup.Engine1.Library.Excel.ExcelModule.WorkbookFunctionValue.HandleClassification(ExcelFile file)