Emulator

What's the problem?
Changing between open gl and dx9 backend sets post processing shaders of opengl to off instead of default in the game ini. This overrides the general option of open gl for that specific game.

Dolphin version with the problem (as it appears in the title bar, Ex.: "R
4779" or "R 6403M"):
r7459

(optional) Dolphin version that does not have the problem:

Operating system and version:
32-bit or 64-bit:
64 bit windows 7
Game ID (as it appears in game properties, Ex.: "GZ2P01" or "RSBE01"):

Build command-line (not on Windows):

Was the ISO a plain dump from disc, compressed and/or scrubbed?

Please provide any additional information below.

When you use open gl and run a game the below lines are created in the game ini after you open the settings.

[Video_Enhancements]
PostProcessingShader =

Then switch to direct 3d 9 and run the same game. Open the settings window. The above lines will change to:

[Video_Enhancements]
PostProcessingShader = off

Now if you change to open gl and enable a post processing shader in the general settings it will not apply to this game since it is set to off in it's ini.