VirtuaNes on pc has some problems

I love the NES game "Mighty Final Fight". I want to use cheats to make the game even more fun to play but whenever I type cheat code (most of them are not considered as cheat codes by virtual NES) which are recognized by Virtual NES and I even enable them 'always' but I did not see any effect of the code. What could be the problem?

Also, in my game there is a fire kick move (possessed by guy) which does not work. To do it: A, backward, forward + B But he does not do the move at all. Is this a problem in the Emulator or my PC or emulators don't support that move? But this is my second problem, I have no problem if it is left unanswered but my main problem is cheats.