I have DotNetOpenAuth running on a background thread making calls to Google authorized with OAuth on a regular basis.

About once a day, which is about one in 10,000 calls, I get the following Exception:

An unhandled exception occurred and the process was terminated. Application ID: DefaultDomain Process ID: 3316 Exception: System.NotImplementedException Message: The method or operation is not implemented. StackTrace: at DotNetOpenAuth.Messaging.ProtocolException.GetObjectData(SerializationInfo info, StreamingContext context) in c:\Users\andarno\git\dotnetopenid\src\DotNetOpenAuth\Messaging\ProtocolException.cs:line 90 at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter, SerializationBinder binder) at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.Serialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter, SerializationBinder binder) at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck) at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck) at System.Runtime.Remoting.Channels.CrossAppDomainSerializer.SerializeObject(Object obj, MemoryStream stm) at System.AppDomain.Serialize(Object o) at System.AppDomain.MarshalObject(Object o)

If it was thrown and caught once a day I'd be fine, but this is a big one - I'm getting this in the Application Error log on the server, and it's crashing the process entirely - the site goes down and restarts.

Has anyone else run into this? Something I'm clearly doing wrong?