Dear Peter,
It is very kind of you.
Since I didn't know what kind of solution I must act, I started from the base (let me say)so upgrading the Direct X (with the last one, Direct X 9a if I do not make mistake), installing the last driver of the Video card (Catalyst 3.4), making some test/changing in the display parameters of the game.
No result at all.
Probably it is a non compatibility between my mother board (ASUS A7V8X-X) and the vido card (ATI 9100 128 Mb).
The last chance could be the Via 4in1my version isn't the last one but practically is one of the newest (if I do not make mistakes the last one is the 4.47 while I "have" the 4.46).
Moreover I do not think this modification will give me a solution.
Only a graphic option is giving some strange result; the "max visibility" of FS2002.
If during the game I face the "bug", I can move the max visibility slot and the bug disappearbut just for a short time; usually I'll find again the bug within few minutes (it seems, but please take my information carefully, that with the highest visibility, 150 Nm, the PC is forced to recalculate the horizon .. but it's not a final solution).
Sometimes I get a temporary solution also moving the slot from max (150 Nm) to min (60 Nm).
It seems no sense ...
By the way, if you have an idea (also, "let the PC jump out of the window" :-) ) could be niceeverykind of test could be the right one.
Ciao !
Maurizio