Site Restore Problem

When I try to restore a site collection using "stsadm -o retore" command it is giving the following error.
"Your backup is from a different version of Windows SharePoint Services and cannot be restored to a server running the current version. The backup file should be restored to a server with version '12.0.0.6318' or later."

I figured out that my SharePoint version is '12.0.0.6300' (Go to any SharePoint site in the system.Click on Site Settings. It will display the version number as attached in screen shot") The solution is to upgrade my SharePoint to version 12.0.0.6318. I found the link for downlod in the following url:

http://www.microsoft.com/downloads/details.aspx?FamilyID=256CE3C3-6A42-4953-8E1B-E0BF27FD465B&displaylang=en

Download it and install. Now the site restore should work.