Question for the Graphics Guru's

I'm rendering a TRichEdit onto the Canvas of a TImage, Foreground color is
clBlack, Background color is clWhite. The Bitmap of the TImage has the
Transparent color set to clWhite.  Then I set the brush color to some other
color (not clWhite) and do a BrushCopy (with the CopyMode set to cmSrcCopy)
to the canvas of the final destination.  Finally I set the Transparent
property of the Destination to True.  Everything works fine, mostly.  On
some PC's the transparent property seems not to work.  On my Win98 test PC
if I set the color resolution above 256 the transparent doesn't work and the
background is always black.  On some NT machines if the color res is set at
36 bits per pixel I get the same result.

Questions:

1.)  I'm assuming that this is a driver issue am I making a valid
assumption?
2.)  If I'm correct about question 1, how do I query the O.S. or driver to
find out if transparent colors are supported?

Thanks in advance.

--

Roy Owen
Servant PC Resources, Inc.