How to make non-Localizable SplashScreen in WPF

Question

I'm just adding internationalization to my next WPF application, and have followed the instructions here.

I then noticed that there would be a fair amount of duplication in the satellite DLL, so marked the images that won't be localized in the .csproj as

<Localizable>False</Localizable>

Unfortunately, one of my resources is used in a SplashScreen thus:

SplashScreen ss = new SplashScreen("Images/splash.png");
ss.Show(false);

And this throws an exception when the Show call is executed. Here's the exception output

A first chance exception of type 'System.IO.IOException' occurred in WindowsBase.dll
A first chance exception of type 'System.Reflection.TargetInvocationException' occurred in mscorlib.dll
Step into: Stepping over method without symbols 'System.RuntimeType.CreateInstanceImpl'
A first chance exception of type 'System.Reflection.TargetInvocationException' occurred in mscorlib.dll
Step into: Stepping over method without symbols 'MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateInstance'
A first chance exception of type 'System.Xaml.XamlObjectWriterException' occurred in System.Xaml.dll
Step into: Stepping over method without symbols 'System.Windows.Markup.WpfXamlLoader.Load'
A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll

Additional information: 'The invocation of the constructor on type 'MainWindow' that matches the specified binding constraints threw an exception.' Line number '4' and line position '9'.

When I remove the False line it works again.

Is there any way to load the resource I want, which is stored in test.unlocalizable.g.resources?