Pop-up: Norton 360 stopped working and was closed

This Pop-up keeps happening.   But when I see Pop-up and check Norton it  appears to be working, i.e. Norton has green boxes checked for Security, etc.    

Did Norton stop working and start again?     If so do I have any security exposure?     Using Windows Vista Home Premium x64

"Norton 360 stopped working and was closed

A problem caused the application to stop working correctly.  

Windows will notify you if a solution is available. "