cups fails to start on boot after upgrade

OS opensuse 12.3 x64; KDE

Cups got automatically updated to version 1.5.4-5.11.1 and now does not start on boot. Hence hp-toolbox doesn't start either ( I have an HP printer installed). Prior to the upgrade both cups server and hp-toolbox started on boot.

I can start cups manually using systemctl and it reports no errors - starts fine, and hp-toolkit also fires up manually without any problems.

There are no log messages of any kind referring to cups in /var/log/messages.

Does anyone know why an upgrade of cups should prevent it starting and why there is no mention of it in the log file?

Thanks