Frequent antivirus update popup

I get popups many times each day, sometimes one right after another, that the anti-virus database is being updated, then has been updated. Does this occur that frequently or is something strange going on? If I click “update” it respondes that no update is needed.

Started From The 1st Half Of May 2009, Updates Were Multiple In A Day And Finally Every 30 Mins. After Every Update, Check Whether The Virus Signature Database version Is Changing. If Its Not Changing, Then Its Not Normal

How do I check the version?

On The Top Right, You Can Find A Tab Miscellaneous
Under Miscellaneous You Can Find About
Select About And A New Window Will Appear
Look For The Virus Signature Database Verion