oh, i missed it. it's said that in the installer.txt:
If you are using AMXX, than only the engine and cstrike modules are needed (booth default module),
no other special or addiotional modules are needed except mysql (only if you save XP via mysql).
but i wonder why if no other module has been used, the plugin doesn't work. the race_choosing_menu is just coming again&ag but no any effect comes out.
ys, i should do more test next time before asking. so sorry about all this.