I tried the 4GB patcher and Catalyst 9.10, neither cured the OpenGL memory leak/CTD problem for me. I seem to get the problem in high particle (explosions, smoke) situations. I've never had it with a dogfight server, only in COOPs with lots of action. I've also posted the problem as feedback at AMD's web site and noticed that the automated form doesn't even include IL-2 as a game listed on their form's pick list. That must be telling me something.
I'm installing Win 7 today and I am seriously considering buying an Nvidia card (prior to) so that my fresh install can be sans ATI. I'm about fed up with this problem. I've given ATI plenty of time to fix it. Too much in my view.