Thanks for the link to the FAQ. I downloaded and installed the files
http://www.battlefront.com/misc/Radeon_text_fix.zip
and it solved the problem. Thank you very much.
Now how do I move my Mac scenarios to windows xp? Are they the same kind of file? Just copy them into the XP Scienarios folder for that particular game. CMBO, CMAk, CMBB. I will order the Windows versions of CMx1 today.