Salute! Sorry for a late answer. I dont know what happend, maybe a partial break down of my grafic card. Anyway, I bought the latest Asus GTS250 512mb "Dark Knight" since I could not find a solution to get as steady fps as I used to have.
Now IL-2 works like a charm. My first measurment was made in may (when I had no trouble with occasional low fps) and BlackDeath showed: 7348 Frames, 28 min, 62 max and 50.641 avrage fps. With new grafics I get: 7911, 28, 62 and 55.081. No bigger change compared to from the time it worked quiet well, but a big difference to what I got when it did not worked that well.
I let the grafics run on default settings and the sceenery look so good. Also I see no fps drop in any wheather conditions, lots of trees, clouds, water, beaches whatsoever. Only when over large citys. My config file I set water to 3, forest to 3 and something else I forgot. Me happy now!
Swep