As far as I remember skype has a problem with v4l2 (video for linux 2) and has to use vl41 instead but it doesn't know were it is the solution was to shutdown skype then create a script. In a terminal type or paste
gksudo gedit /usr/local/bin/skype
and add these lines for a 32bit system
or these lines for a 64bit system
then type or paste this line in the terminal which will make the script executable
sudo chmod a+x /usr/local/bin/skype
after this you can open Skype and check in options/video devices and hit the test button.
this should make it possible to see your own webcam and others in skype.
Hope this helps.