Two additional things I have noticed since installing the 5.4s. First, my Window, while maximized, flickers. Not a refresh rate issue, but the border starts to move in and out in a flickering action.
Second is the Source engine. Loading HL2 and CSS map takes forever now with a huge FPS hit. I'm talking unplayable at an actual 2 FPS. Sometimes the map won't even load. Actually re-downloaded Steam and all the games

, which did not cure the problem. Went back to the 5.2s and inserted the 5.4 OGL driver because I am so happy with it. All good now.
The latter greatly saddens me because of the noticeable image improvement with DirectX and the 5.4s. I see instead of Multimedia drivers, WDM drivers are installed with DOS opening up now with the 5.4s. Could this change be causing any problems?