[Erel]

As Robert mentioned there is a problem with loading an image when the transparent property is true.
Unlike the Image control the ImageButton doesn't create a copy of the image, therefore you should manually create such a copy if you get the image from an external library or an ImageList:

Sub Button15_Click
    ImageButton3.Transparent = false
    ImageButton3.Image=IL1.Item(13)
    ImageButton3.Image = ImageButton3.Image 'Creates a new copy.
    ImageButton3.Transparent = true
End Sub

These two issues will probably be solved in the next update.