subscription issue - how many computers can I put my Norton IS on?

I checked my account and I paid $59.99 plus tax for NIS on Aug. 26, '10.  I have NIS on two computers now and wanted to put it on my new netbook but my account info says I have protection for 1 computer and no activations.  What is weird is that the serial number and product key and expiration date are the same on both computers, which makes me think it's the same subscription and I should have another activation left, so  I'm wondering why, if I paid $59.99 I don't have a third activation available.

 

Thanks,

Wendy