Problem on RadioBoxes with wxRuby

I got a situation on wxRuby using Wx::RadioBox.

My radioboxes got some ugly background & borders like that :

Unlike the demo which got a better style when I run it :

here is my code :

#!/usr/bin/env ruby
# coding: utf-8

require 'wx'
include Wx

class MainFrame < Frame
    def initialize()
    super(nil, :title => "Title", :size => [ 480, 400 ])
        #sizer = Wx::BoxSizer.new(Wx::VERTICAL)
        sampleList = ["Choice1","Choice2","Choice3"]
    rb = Wx::RadioBox.new(self, -1, "Title1", Wx::Point.new(15,20), Wx::Size.new(100,200), sampleList, 1, Wx::RA_SPECIFY_COLS, DEFAULT_VALIDATOR, "Name1")
        evt_radiobox(rb) {|event, other| on_debug(sampleList[event.get_int()].to_s(), rb.name.to_s())}
        #sizer.add(rb, 0, Wx::ALL, 20)
    rb2 = Wx::RadioBox.new(self, -1, "Title2", Wx::Point.new(150,20), Wx::Size.new(100,200), sampleList, 1, Wx::RA_SPECIFY_COLS, DEFAULT_VALIDATOR, "Name2")
        evt_radiobox(rb2) {|event| on_debug(sampleList[event.get_int()].to_s(), rb2.name.to_s())}
        #sizer.add(rb2, 0, Wx::ALL, 20)
        #set_sizer(sizer)
    #sizer.fit(self)
        #sizer.layout()
  end
  
  # show a 'Debug' dialog
  def on_debug(*params)
    Wx::message_box("Debug :\n\r\n\r#{params.inspect}",
        "Debug Box",
        ICON_INFORMATION|OK)
  end
end


class MyApp < App
    def on_init
    frame = MainFrame.new
    frame.show
    end
end
MyApp.new.main_loop()

And here is the default code :

• samples/bigdemo/wxRadioBox.rbw
• It seem's that this code is different from the one on your wxRuby install present in C:\[your Ruby Install]\lib\ruby\gems\1.9.1\gems\wxruby-ruby19-2.0.1-x86-mingw32\samples\bigdemo

Any help will be highly appreciated because I really don't know why the aspect is so much different?

Problem solved by setting up a default background color on the main Frame : self.set_background_colour(Wx::NULL_COLOUR)

and here is the code :

#!/usr/bin/env ruby
# coding: utf-8

require 'wx'
include Wx

class MainFrame < Frame
    def initialize()
    super(nil, :title => "Title", :size => [ 480, 400 ])
        #sizer = Wx::BoxSizer.new(Wx::VERTICAL)
    self.set_background_colour(Wx::NULL_COLOUR)
        sampleList = ["Choice1","Choice2","Choice3"]
    rb = Wx::RadioBox.new(self, -1, "Title1", Wx::Point.new(15,20), Wx::Size.new(100,200), sampleList, 1, Wx::RA_SPECIFY_COLS, DEFAULT_VALIDATOR, "Name1")
        evt_radiobox(rb) {|event, other| on_debug(sampleList[event.get_int()].to_s(), rb.name.to_s())}
        #sizer.add(rb, 0, Wx::ALL, 20)
    rb2 = Wx::RadioBox.new(self, -1, "Title2", Wx::Point.new(150,20), Wx::Size.new(100,200), sampleList, 1, Wx::RA_SPECIFY_COLS, DEFAULT_VALIDATOR, "Name2")
        evt_radiobox(rb2) {|event| on_debug(sampleList[event.get_int()].to_s(), rb2.name.to_s())}
        #sizer.add(rb2, 0, Wx::ALL, 20)
        #set_sizer(sizer)
    #sizer.fit(self)
        #sizer.layout()
  end

  # show a 'Debug' dialog
  def on_debug(*params)
    Wx::message_box("Debug :\n\r\n\r#{params.inspect}",
        "Debug Box",
        ICON_INFORMATION|OK)
  end
end


class MyApp < App
    def on_init
    frame = MainFrame.new
    frame.show
   end
end
MyApp.new.main_loop()