New fsx.cfg and I disabled IF weather and created my own weather, using the custom option in FSX, and everything worked fine.
When I then re-enabled IF and tried it again, the whole sea around me blinked like it had a layer made up of polygons (triangles) laid over the surface. Maybe this makes sense to you but I've never seen this effect before.
Video 1 -
http://www.youtube.com/watch?v=FSPytsE4OWEVideo 2 -
http://www.youtube.com/watch?v=ECDRaqHLXmMI also saw the stratus you mentioned but it was in strips, in places, and looked most out of place, see video above.
Then I tried ASE weather, with IF weather disabled. I saw the typical ASE flashing sky and sea while the weather updated and was injected but after that everything was normal. A few clouds that intersected the mountains around CYVR were jittery but in general it was ok.
This weirdness is unique to IF, as far as I can tell, and is not related to:
1. Custom scenery
2. Custom aircraft
3. GEX, UTX, ASE, REX
I run Win 7 64bit, latest drivers, 2xGTX 580 3gb, i7 2600k and everything is ship shape with my system. FSX runs like a dream, except around KJFK

, and the weather and atc add-ons that I use work ok.
Let me know what information you need.
Thanks,
Toby