When you says "rf stops responding and closes" is? the Client is close or Zoneserver close?
The Client is close = You have something wrong in your RF interface, rf_online.bin, *.edf, *.spr files or something else
The ZoneServer is close = many hackers doing this to break your DB and f*ck off your server. well... to solve that have to restore the DB again and get some zoneserver antihack, there are solutions without having to do wipe but you have to know what the table is broken to replace the data