It can take up to 24 hours for the subscription status to update in OneCare after you have updated on the Billing site.
If you are still receiving the renewal warning, please verify that the renewal is showing at http://billing.microsoft.com
Then, verify that the date and time on your PC is correct, open OneCare and click Check for Updates.
If it still does not update your subscription status in OneCare, contact support -
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve