well if you are adding it on top of your other effect then that could be why, but other than that i have no clue as to why it wouldn't work if it wasn't one of the things i suggested... have you tried it on a clip that doesn't have any effects on it?
either way i think your effect looked good as is, if you like it that way then i wouldn't worry about changing it too much
Maybe I'll try again with the Glow effect some other time... for now I decided to follow your advice and keep the Luminance mask, which also includes itself a sort of Black and White effect I was trying to create. Thanks for your time, I'll let you know when my video is done if you wish
(about 45% done...)
You laugh at me because I'm different, I laugh at you because you're all the same