Sadly this issue is a driver problem with AMD is it not?
I'm visiting my folks in winnipeg right now, and actually helped my stepdad swap out a 4850 for a gf275. What a difference in the visuals (tweaked for both cards of course).
There are STILL opengl issues for AMD/ATI users who want to play IL2, despite the fact it's ancient software by modern standards (no offense to devs or TeamD members intended). We've been able to milk this one for a long time. I'm sure many of your fans would be most grateful if you (team D) could find a way to work with ATI/AMD to correct this long standing issue.
Thanks for listening.