You will not be able to run this command with server side sv_cheats turned off since this is one of those commands that requires sv_cheats to be enabled serverside to work.
You can use this:
http://forums.alliedmods.net/showthread.php?t=92289
to send sv_cheats 1 to a client and see for yourself.
However there is a chance removing addcond's cheat flag would remove its dependency on server side sv_cheats. However this is unlikely since other commands like thirdperson do not lose their dependency.
This is a better way to handle the sv_cheats,
PHP Code:
stock TF2_AddCond(client, cond) {
new Handle:cvar = FindConVar("sv_cheats"), bool:enabled = GetConVarBool(cvar), flags = GetConVarFlags(cvar);
if(!enabled) {
SetConVarFlags(cvar, flags^(FCVAR_NOTIFY|FCVAR_REPLICATED));
SetConVarBool(cvar, true);
}
FakeClientCommand(client, "addcond %i", cond);
if(!enabled) {
SetConVarBool(cvar, false);
SetConVarFlags(cvar, flags);
}
}
stock TF2_RemoveCond(client, cond) {
new Handle:cvar = FindConVar("sv_cheats"), bool:enabled = GetConVarBool(cvar), flags = GetConVarFlags(cvar);
if(!enabled) {
SetConVarFlags(cvar, flags^(FCVAR_NOTIFY|FCVAR_REPLICATED));
SetConVarBool(cvar, true);
}
FakeClientCommand(client, "removecond %i", cond);
if(!enabled) {
SetConVarBool(cvar, false);
SetConVarFlags(cvar, flags);
}
}
This way the replicated flag is also removed so sv_cheats 1 is never sent to the client and only changed serverside.