I too have this bug. No vanilla minecarft sounds. you can press f7 to disable the bird and water noises. i even got a philosophers stone and charged it up for the sound effect. all the modded sounds work as far as i know, but all the vanilla sounds are gone.
And what does this mean? is there a config we can change to make tekkit download from the right.. server/http/ wherever the hell the sound files come from?