Ran into a serialization problem with WCF the other day that was rather interesting to find and fix. It wasn't a problem with WCF, in the end, but rather with what we were telling WCF to do. So we have some complex entities that we're shoving through the serialization layer. We also send through lists of these entities, and the list may have references to itself. To keep our list sizes small, we've implemented a DataContractSerializerOpera... where when we create the data serializer, we...