public class Foo
    {
        private string _str; // -)

        public Foo(string str)
        {
            _str = str;
        }
    }

I've submitted a patch upstream which allows access to private and protected 
members when you create a type accessor like:

var accessor = TypeAccessor.Create(typeof(yourClass), true);

The patchset is attached to this comment.

I applied the patch and I still only get public members returned.

If you look in MemberSet.cs @ 16, it makes sense because type.GetFields() only 
returns public members if there are no arguments.

Adding:
BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance

to the arguments of that method call does seem to work. 

Oh well, that didn't work either. Apparantly you can't access private fields, 
you'll get an exception if you try. See here:

http://stackoverflow.com/questions/6356371/help-needed-with-typeaccessexception-
attempt-by-method-to-access-type-f