FS 2004...

Win XP Pro SP2
A rather annoying problem I have, with these "artefacts" constantly appearing in my clouds as I fly, for months/years now!
The flights starts of normally and the artefacts appear over time and can only be cleared by "Refreshing" the screen...(IE: calling up the FS Navigator screen, then returning back again to the flight).
It always occurs with Default FS 2004 Custom Weather Clouds, or Real Weather Clouds.
No problem with "Clear Skies", obviously!
I have had this problem with my previous Card; AGP nVidia 6600 128 MB...
...and now with my present Card; AGP nVidia 7800GS 256 MB.
No Over-clocking involved anywhere, and no problems with overheating, loads of well lubricated fans, no dust, biscuit crumbs, Spiders, Mouse Poo, everything running cool, and no obstructions to air flow....

Specs:
Desktop (Table-top) Computer Case...(Not a Tower!), so all the cards are plugged vertically for better airflow over all of them!
Win XP Pro SP2
AMD Socket A, Athlon Thoroughbred, 2600+ (2.1 GHz).
Winfast AGP nVidia 7800GS 256 MB.
750Watt PSU.
I can cope with it, but it is rather annoying....
...by the way is there a key-press in FS 2004 which will automatically "Refresh" the screen whilst flying?
...any ideas, ring a bell, Chums?



The clouds illustrated in the above pics are "Oscar Clouds", but the same fault occurs with the FS 2004 Default Clouds!
F...on Cloud #9 in between times...

PS...Pics: In my lovely Cessna 150_V2 Aerobat...

P.P.S. The same fault often appears in the Prop animation, and is cured by "refreshing" the screen!