Many usb audio devices in my experience do not perform well with dsnoop and/or dmix, thus is it quite improbable that 7.04 will ship with dmixed/dsnooped usb-audio.
-- ALSA dmix not enabled by default for usb sound devices https://launchpad.net/bugs/33736 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
