Who woulda thought, IList<> kills WCF

It can't be that hard!!! I keep telling myself this. I'm writing a WCF application right now and I've been running into loads of problems trying to configure things. ABC right? Set my address, contract, and binding....how hard can it be?? Why is a horrible ExecutionEngineException being thrown and taking down IIS with it??? http://connect.microsoft.com/wcf/feedback/ViewFeedback.aspx?FeedbackID=433569 Turns out you can't have an IList<> of DataContracts.