you can always try a different programm, also another version of wadmanager can help (google)
or use multimodmanager to install your wad files MMM Guide.
if all does not help or end blackscreening follow the HBC apps section of this guide.
what maybe is just a typo. there is no v20 of neogamma, strong guess you want to update your cIOS (to rev20) along with neogamma, get the Latest Neogamma here.
that makes me think you want to run Call of Duty and for that i can tell you exist a guide as well Call of Duty: Black Ops
good luck for now (if Black Ops applies, please keep questions regarding the game in the guide.)
edit: also you missed to say Hello in the Introduction section.