Before installing alsa 1.0.11 on my system,
"/dev/dsp1: Device or resource busy" often occurred when I hung up the call.
But everything is ok for skype using alsa 1.0.11.
I hang up calls in any way and "/dev/dsp1: Device or resource busy" never occurs.
I thinks everyone can try to install alsa 1.0.11 if he has that bugs.