The game.qvm should either be in /usr/local/games/tremulous/base/vm/, or ~/.tremulous/base/vm/ (where ~ is the home directory of the user running the server). Not sure what you mean by "the [user] map of tremulous in /", if you mean that you have /base on your system then you'd need to tell tremded where to find that with "+set fs_homepath /". But I'd recommend keeping the homepath somewhere other than the root of your filesystem.