Norton Antivirus for Mac - How to Renew?

I am using Norton Antivirus for Mac, version 11.1.2 (17).  I am not on Lion.

 

In following the annual renewal notices, it invariably offers me only the PC version to renew.

 

When I follow the link "Renew Product for Mac", it also asks me for the PC version number, and tries to sell me the PC version. There are no other options for changing version or platform.

 

How in the heck do I renew my product?

 

Thanks for any thoughts.