full system scan too often

Vista Home Premium and (I think) NIS 2009 - 16.7.2.11

It appears to me NIS runs a full system scan 2-4 times a day between 7A and 7P

I think I have it set for daily at 12:15A by going to

Computer>Settings>Computer Scans>Manage Scans>Configure.

Nonetheless, most business days I get at least 2 scans during the day.

How do I stop the scans during the day?

How do I start the nightly scans?