Skype 4.2 for Linux is available only for 32 bit version. If you badly need the 64 bit version of skype, you have to install an older version of it (4.1 or earlier).
To fix the webcam problem, you need to use the 32 bit version of Skype and 32 bit version of libv4l-0 library.
You can get skype form the Skype website or from the Ubuntu Software Center (you need to tick the Canonical Partner Repository).
And to install the 32 bit version of libv4l-0 library:
sudo apt-add-repository ppa:libv4l/stable sudo apt-get update sudo apt-get upgrade
As Skype 4.2 is a 32bit binary, you need install the 32bit libv4l-0 package:
sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install libv4l-0:i386 The solution is found from: http://linuxtv.org/wiki/index.php/Libv4l_Upside_Down_Webcams