ETNam unfortunately is buggy and the developers stopped working on it. I can recall some issues with tripmines (random crashes), maps (random crashes on Tankbuster and few more) and GUID (security kicks for false spoofing - next time disable it in settings, setting a person without GUID adds lvl to all without GUID etc.). Still it's my favorite mod, too bad it's dead. Hard when playing 1st time, but after 4-5 games it's quite easy.