I'm using Skype in Ubuntu 10.04 and unable to communicate via video call as i cant enable sound recording. So, i've installed GNOME Alsa Mixer and changed some settings and it WORKS now !!!
Just few steps and sound recording works.
1) sudo apt-get install gnome-alsamixer
2) Go to Application > Sound & Video > GNOME ALSO Mixer
3) It will open a control panel
4) Just check the Rec checkbox and control the volume for capture