Parse.Android.dll error when using linker or release mode - Xamarin app

Question

When using the Parse.Android.dll with the Xamarin linker (Linking SDK's only) in Release mode I get the following error from a query:

Unable to evaluate the expression: "createdAt"

The query is simply:

var query = from i in ParseObject.GetQuery("contentitem")
            where i.Get<DateTime>("createdAt") > dtForQuery
            select i;

This works just fine in Debug mode and also works fine when I disable linking. Unfortunately, when I disable linking I'm left with a file of 36Mb which isn't going to work. What should I be excluding from the linker to avoid this?

I've seen references to internet access not being available etc... tried everything. Debug or linking on, and I have the error.

Help?