spotlight stops searching contacts

Hi, this one is a 'baffler' - new state of puzzlement.

After upgrading to Mountain Lion spotlight would occasionally stop searching my contacts, the artist previously known as Address Book. The Spotlight preference box for Contacts is ticked, and the Privacy tab does not have anything listed. Occasionally it would start searching Contact again after a re boot, but this is a mac and shouldn't need that. Now even that doesn't work, I can't get spotlight to search contacts at all. I have also added my HD to privacy, then removed it off forcing it to re index everything, which takes a while. It would work after that then stop after a few days.

I am normally not alone if ever I have a problem and find helpful solutions in forums etc. But alas, I seem to be on my lonesome on this cold dark night.

Any help appreciated, thanks.