[cravenge]

After some digging around, I think setting "sv_maxplayers" to 1 may not be a good idea at all since not only the slots are limited but also the global MaxClients variable of the game is changed as well and most internal functions rely on the UTIL_* ones that seek the value of this variable which in turn would cause some strange oddities.

Maybe blocking mid-game connections through OnClientConnect (SM) / OnClientPreConnect (ConnectHook extension) would be a better solution?