“Flashing” or flickering gauges have plagued both the 737 and F421 sim PC’s. Both are running good graphics cards, both are running Win7x64… I *know* both of these machines ran FS9 nicely under Windows XP.
After a bit of google searching and forum reading I had no clear fix, or even a cause!
Tonight I installed and ran nVidia Inspector, applied my favorite settings, then disabled Anti-Aliasing, and texture filtering inside fs9 and voila! no more flashing/flickering gauges!