Re-activating Norton Internet Security using a different Product Key

Over the past several years I have licensed Norton Internet Security on several computers.  Some of those licenses were for multiple PCs, others were not.  I now have one computer with less than a month on it's license, and I would like to re-activate it using one of my other licenses that has available PCs left and doesn't expire until 2013.  I upgraded the software to version 2011, hoping it would just let me activate it using the desired Product Key, but it re-activated using the Product Key set to expire in less than 30 days.  So I selected "renew" from the main product screen and entered the desired Product Key, which it appeared to accept.  Then it returns saying activation completed, you have 26 days of protection remaining!  In other words, it used the old Key, not the one I entered.  How can I re-activate using the Product Key from the other license? 

 

Thanks,  Rick