The password setting in podbot.cfg is loaded at server' start. Did You restart the server after changing the password in podbot.cfg?
The command
pb menu
should be called from the client's console. The way to get the access to podbotmenu is the same like for AMXMODX with password method. If You can get the access there using the password (not by IP, not by Steam_ID etc) the podbotmenu should be working. I You have read
that topic and You cannot solve the problem with podbotmenu access, I suggest to use this plugin:
http://forums.alliedmods.net/showthread.php?t=51745