i read it somewhere in the QEMU README, that if compilations complains about -lasound you should recompile libsdl, and you could get the rest of the sdl modules, like SDL_sound, and SDL_mixer, smpeg, just download and compile all of those with ./configure --prefix=/usr it is usefull to "telinit 1" run ldconfig then telinit 3 or 4 then recompile QEMU

about the DNS error, i don't really know as i hardly know much about networks, but is your machined using loopback network interface ? if not then try loopback, at least it works here fine running slackware 10 upped to current got Slack? get counted