The example I find in http://www.softwarecrew.com/2010/09/review-norton-internet-security-2011-why-its-our-pick-of-the-current-security-suites/ is a warning about one particular program and has a "details" link in the pop-up window. Does yours mention a particular program? If so, what? And does it have a details link? If so, what are the details.
The System Insight chart gives you insight into your system. If you don't want that, don't run it. But now you did that you might want to find out the details and see if you can do anything about whatever causes Norton to warn you about a program that uses more memory than it thinks acceptable.
Kees
Just installed Norton 2011 and get this report on a pop-up, High Memory Usage. What does it mean and what is too high?
Thanks

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic