For me its increased with this patch......... previously a simple pre firing of the guns would prevent it now every time I fire I get it with an initial couple of white flashes where the graphic should be.
I am also getting it on take off as slats an gear operate simultaneously.....and on other odd occasions where there are multiple ac about.
Textures at 256 top 2 sliders at 90% range 3 miles and bottom at 1. Mipmapping on.
My sound hardware is set at 75% now.....rest as dxdiag below.