public void DrawCheckbox(Gdk.Window win) {
		System.Console.WriteLine("Drawing checkbox here: ");
}


than cilc generates for me:
void embed_engine_draw_checkbox (EmbedEngine *thiz, GdkWindow *win);

looks good

i call that from my application:
embed_engine_draw_checkbox (engine, window);

and get:
Native stacktrace:

        /usr/lib/libmono.so.0(mono_handle_native_sigsegv+0xd9) [0xa76d4759]
        /usr/lib/libmono.so.0 [0xa768392b]
        [0xffffe440]
        /usr/lib/libmono.so.0 [0xa76b204c]
        /usr/lib/libmono.so.0(mono_runtime_invoke+0x33) [0xa77203b3]
        ./libmonogine.so(embed_engine_draw_checkbox+0x71) [0xa7f6d551]
        ./libmonogine.so [0xa7f6bef9]
        /usr/lib/libgtk-x11-2.0.so.0(gtk_paint_check+0xd9) [0xa7daea39]
Aborted (core dumped)