As some have said, I'm not seeing shadow mask either. Downloaded the new aperture.png posted above and made sure it was specified in MAME.ini. Still nothin. I'm also having the same problem with jitter turning off once the menu/slider is closed. Also Phosphor Defocus, Phosphor Life, Curvature, and Scanline Overdrive are not working.
in u5 HLSL Many of the RGB settings were not working for me. They're working fine now in this build. Was kinda hoping these were a few bugs being worked on and not a conflict with my graphics card.
Hopefully by the time Mame 143 comes out all these will be fixed up. I'm sure the final version will be amazing!