Unity is crashing while making a web service call

Over the past day or so I've been struggling to use a wcf service with Unity. We already have web services hosted using Agatha/WCF. Using the tutorial from http://wiki.unity3d.com/index.php?title=Webservices_In_Unity I generated a service client using svcutil and then created a simple class to make a request, just as shown in the tutorial. However, when I play the scene Unity simply crashes.

I added a breakpoint in monodevelop and then ran the the scene to try and get more information and I end up with a System.StackOverflowException. The stack trace looks to be coming from inside Mono itself.

I see text like this repeated over and over. At this point I created a separate monodevelop project to try out the c# code. I modified the code to not use Debug.Log and just write to the console and the service call was successful. So it would appear that the export of the web service was successful with svcutil and that the code itself is fine. It seems there is some sort of unique thing happening within Unity. I'll note that I'm using Unity 3.5.5f3 with the built in Mono version on Windows. I even got the same behavior (Unity crashing) by playing the scene with Unity 4 beta on a mac.

Just as in the tutorial I dropped in the System.Runtime.Serialization and System.ServiceModel assemblies from the Mono folder into the plugins directory so I believe those are referenced correctly since I don't get compile errors from Unity.

What I'm looking for here are other troubleshooting steps I can take or if there is something else I am missing here. Any help/suggestions would be much appreciated.