Comment # 1 on bug 1185325 from Michael Andres

Could you please attach your /var/log/zypper.log containing the "zypper
purge-kernels" command, or create a log file to attach
(/tmp/1185325.zypper.log) by running  

   ZYPP_LOGFILE=/tmp/1185325.zypper.log  zypper purge-kernels