Fonts On Button Text Image Unreadable ?

Using XP and VB 2008 Express for development of Widows Forms App.I am setting a button's .text to "" and then assigning a bitmap with some text written on it to the button's .image. Everything looks great on the development compter, but is almost unreadable on test computers using Vista and Windows 7. This despite trying a number of different combinations of (standard?) font family and size (including Arial, Verdana, Microsoft Sans Serif). Why?

Details....I have a button on a form (32 pixels x 32 pixels).I set the button.text field to "". I create a bitmap a little smaller than the button, and DrawText on it (I can't simply use the button.text field because I want to place text in different areas of the button and draw special characters.I use the following code to create the bitmap:

m_bmpDrawingSurface = New Bitmap(30, 30, Drawing.Imaging.PixelFormat.Format32bppArgb)
Dim objGraphics As Graphics
objGraphics = Graphics.FromImage(m_bmpDrawingSurface)[code]...

I wonder if somehow fonts are being anti-aliased or otherwise cleaned up by the system on the development computer, but not on the other computers. I also wonder if I should be creating just a simple 30 pixel x 30 pixel bitmaps, or perhaps should be trying somehow to get the buttons 'device context' or something. Or, is there an alternative to DrawString that draws text more intelligently than just setting the nearest pixel either black or transparent, which is what seems to be happening (ie, no anti-aliasing or creation of shades of gray). Maybe another pen? Is there an "anti-aliasing" pen?