Renewal being treated as a second product!

I clicked on renew on my desktop window in my Norton IS 2011 product.   It prompted me for the license number.   After I entered it, I see my prior license still has 20 days remaining, and instead of adding to my subscription, Norton seems to have this set up as a new product in my account.  Why?   What can I do to get my current subscrition extended, instead of a second instance being added to my account?