Norton 360 on Intel Mac Mini OSX 10.8.5 Suddenly Status changes to Unlicensed

I've had this before about a month ago and online support took over my machine, Repaired Permission to main drive then re installed N360. This has happened again today, just after a new update for Itunes so that IOS can be loaded onto Iphone and Ipad,

I have done a Repair (and there were errors) bur still have to reload Norton 360.

 

Is this a known issue with OSX or is it just my bad luck..?

 

Thanks

 

Phil