[KWo]

Try to do one step more. Remove the plugn like You had it before.
Find at Your client's PC in the main cstrike folder the file called config.cfg (or whatever it is called under linux - the file which contains all Your binds).

Add at the end of that file those lines:
bind "=" "pb menu"
setinfo "_pbadminpw" "your_password"

Make sure there is no other lines binding "=" in Your config.cfg.
Check if after joining the server it works.
Make sure You are the full access to amxmodmenu (to fully control AMX X).
From that what can see right now it looks like they are linux users they have troubles with podbotmenu. Check what You need to do to get the access to amxmodmenu on Your linux DS. Getting access to podbotmenu is similar but less complicated (in podbot mm there is no so many levels/flags to get the aceess to separate parts of AMX X).