It’s recommended to install Skype from the Ubuntu repositories rather than the download from Skype.com. In doing so, it can be beneficial to install the package listed below as well.
If you experience Skype crashing or locking up frequently on 64-but Ubuntu 13.04, try installing the following. It fixed it for me:
sudo apt-get install libasound2-plugins:i386
Please feel free to comment below.