If there are updates listed as available, then these need to be selected and installed. It is possible that they have already been downloaded to your PC, but have failed on installation, hence the report that they are missing on your PC.
Since OneCare is at risk due to the problem, you can contact OneCare support -
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
Or you can check the solutions via the Windows Update Solution Center - http://support.microsoft.com/ph/6527
-steve