Located in your cstrike/cfg folder open autoexec.cfg. If the file does not exist, create it. Add the following line.
zb_active 0
Located in your cstrike/cfg folder open server.cfg. If the file does not exist, create it. Add the following lines.
es_xdelayed 0.3 es_xload gungame51; zb_active 1
Remember that you should not have "es_load gungame" in your autoexec.cfg if you are doing this since you are now loading it from the server.cfg.
RideGuy