UseOriginalPostProcessing causes slight resolution misalignment? It looks like the correct resolution but moire effect is visible.

I tried disabling/enabling every other effect, changing the native resolution, windowed, fullscreen, force borderless, disabling AF, EdgeAA, temporal.
On Windows 7 GTX580 driver 353.62 ENB 278
(not using SweetFx or any custom enb)
Also tried enb v0.150 and enb v0.216
edit: rolling back to v0.150 and editing shader enbeffect.fx
Code:
//use original game processing only, with vanilla bloom
//#define ENB_FLIPTECHNIQUE
to
Code:
//use original game processing only, with vanilla bloom
#define ENB_FLIPTECHNIQUE
Will make the moire/aliasing much worse....maybe this is a clue?
Edit2: It's actually similar to the diagonal bug mentioned here,
viewtopic.php?f=21&t=4498only it's worse and only effects the bottom right half of the screen.