I've always had this problems with skype and pulseaudio on ubuntu. Whenever i start up skype, i have to call someone, then hang up 4-5 times, before the other person can hear my voice.
When i, or the other person hang up, skype tends to lock up. I can't kill it with "killall skype" or a logout, so i have to restart my computer.
Have anyone else encountered this problem, and if so solved this? I'm using 10.10 btw.