This seems to be exactly what's happening on my work PC. I've installed a font with 21 typefaces, yet only one or two will show up at a time. They show as installed via control panel > fonts, and they're in the registry, but they will not work. I've wasted so much time trying to fix this, and now I'm mid-design with fonts that will no longer work. Very frustrating. I posted to Adobe last time this happened and didn't get a solution.
I've tried every fix in this thread, and others, but I still cannot get this font installed.
When you used FontForge what were the steps you took exactly? Which field did you edit? I would imagine you'd have to reinstall the fonts after editing? I tried messing with this months ago, the last time I went through this nightmare, but I never got it working.