NIS displaying Full Scan continually.

I'm running NIS 2009 with the latest patch, on MS Vista Home Premium.

 

Within the last day or so I keep getting a display on the desktop from NIS telling me that it's performing a Full Scan in the background. This is not right because I manually carried out a scan earlier in the day. LiveUpdate is kicking in multiple times a day suddenly also, maybe as part of the scan process? I checked whether it was actually scanning in TaskManager, and found that it wasn't listed as working. This is not an Idle Scan. Previous versions never did several Full scans, and they have not been configured.

 

Is this a known issue? If so, why is it happening and how do I cure it?  Any help would be fantastic.

 

Many thanks.