Show Image with Combo Box on Ribbon Framework

Mar 18, 2013 at 2:34 PM
Hi,
I am trying to insert an Image with a combo box like this sample of the MSDN Ribbon Framework.

Image

Here my code:
Dim bitmap As Bitmap = New System.Drawing.Bitmap("C:\Users\thomas\Res\FillWithBlack.bmp")
            bitmap.MakeTransparent()
_comboBoxFill.Label = Msg.ComboBoxFill_LabelTitle
            _comboBoxFill.SmallImage = _ribbon.ConvertToUIImage(bitmap)
The Label is shown but the bitmap not.
I tried with a lot of bitmaps including some used for other ribbon commands, no of them are shown.
Anybody can show a bitmap like the sample of MSDN?

Thanks

Thomas