I'm able to load and access resx files in Simulator builds of my iPhone app built using MonoTouch. The resx file entry in the csproj file looks like:

  <ItemGroup>
    <EmbeddedResource Include="MapMenu\Resources\MapMenu.resx">
      <Generator>ResXFileCodeGenerator</Generator>
      <LastGenOutput>MapMenu.Designer.cs</LastGenOutput>
    </EmbeddedResource>
  </ItemGroup>

The .resx file itself has an entry like this:

  <data name="Main_Menu" type="System.Resources.ResXFileRef, System.Windows.Forms">
    <value>Main Menu.mm;System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089;Windows-1252</value>
  </data>

and the generated MapMenu.Designer.cs file has this:

    internal static string Main_Menu {
        get {
            return ResourceManager.GetString("Main_Menu", resourceCulture);
        }
    }

As mentioned above, calling the Main_Menu accessor works fine on the simulator. On the device, however, it produces:

<Notice>: Unhandled Exception: System.MissingMethodException: No constructor found for System.Resources.RuntimeResourceSet::.ctor(System.IO.UnmanagedMemoryStream)
<Notice>:   at System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes) [0x00000] in <filename unknown>:0 
<Notice>:   at System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes) [0x00000] in <filename unknown>:0 
<Notice>:   at System.Activator.CreateInstance (System.Type type, System.Object[] args) [0x00000] in <filename unknown>:0 
<Notice>:   at System.Resources.ResourceManager.InternalGetResourceSet (System.Globalization.CultureInfo culture, Boolean createIfNotExists, Boolean tryParents) [0x00000] in <filename unknown>:0 
<Notice>:   at System.Resources.ResourceManager.GetString (System.String name, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0  
<Notice>:   at MapMenu.Resources.MapMenu.get_Main_Menu () [0x00000] in <filename unknown>:0 

Did a few sanity checks, and am wondering at this point if this really is missing functionality in Monotouch.

Thanks,