TypeLoadException when using Newtonsoft.Json inside PCL

Question

I ran into a lock problem ... I have a project (iOS, in this case) linking to the PCL (made by me), which itself refers to the portable version of Newtonsoft.Json

App → My PCL → Newtonsoft.Json

Everything compiles just fine, but at runtime when using my PCL method that calls Newtonsoft.Json, I get a TypeLoadException

Example: A simple PCL referencing Newtonsoft.Json Portable, with one class like this:

public class MyClass {
    public int Test() {
        var json = @"{""t"":16,""s"":""test""}";
        var o = JObject.Parse(json);
        return o["t"].Value<int>();
    }
}

A simple one-button application with this event handler:

partial void Test() {
    var c = new MyClass();
    var i = c.Test();
    new UIAlertView("", i.ToString(), null, "Close").Show();
}

I get a TypeLoadException when I click a button in the line "var i = c.Test ();"

Even stranger if you replace this:

return o["t"].Value<int>();

with this:

return (int)o["t"];

I no longer get a TypeLoadException, but a MissingMemberException, with this message:

Newtonsoft.Json.Linq.JToken:: op_Explicit (JToken) /Users/Ingham/Projects/TestPCL -iOS/TestPCL-iOS/bin/iPhoneSimulator/Debug/Newtonsoft.Json.dll, /Users/Ingham/Projects/TestPCL -iOS/TestPCL/bin/Debug/TestPCL.dll

, ...

PCL, ...

? !

(Xamarin.iOS): https://www.dropbox.com/s/lsclrg5d1cor1dk/TestPCL.zip