I suspect that you have purchased multiple retail copies of OneCare and have activated a subscription with a LiveID, using the first retail key. You then installed and activated on the second PC with that same LiveID to make that part of the same subscription.
On the 3rd PC, if you wanted to activate a different subscription with a second retail copy, you need to use a different LiveID to start a new subscription, at which point you will be prompted for payment or a key. If you used the same LiveID, OneCare would simply see the active subscription and activate without prompting you to start a subscription.
So, with your 8 (or 9) additional keys, you need a *different* LiveID for each subscription, which allows up to 3 PCs to exist on a subscription.
A single LiveID can only have one active OneCare subscription associated with it.
Instructions on how to reach support are here:
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve
