1) Delete currently installed Skype
zypper rm skype
2) Delete hidden file .skype in the user home directory.
3) Make sure you have installed libpng12-0 package. Install it by YaST if needed.
4) Grab the current Skype version from http://www.skype.com/intl/en/get-skype/on-your-computer/linux/ and install it. You can also install it directly, e.g.
rpm -Uvh http://download.skype.com/linux/skype-22.214.171.124-suse.i586.rpm