It is better to remove the old version and install the new one only. Otherwise there is a possibility that it may make conflicts.
I assume you are referring to the Online account screen where it shows the information regarding two subscriptions is from your account page !!!! What the CD sleeve mentions is that if you already an existing McAfee program on your PC and install another version, it would remove the exsting version off the PC.
Now , getting back to your original question : With the email address that you have registered on our forums , I do see 2 McAfee Antivirus Plus subscriptions , one good until 1.18.2012 and the next 12.16.2012 . If these are the subscriptions that is installed on your subscription they would automatically pick the new expiry date after the first once expires .
If not, I would suggest you to press (Ctrl + D) now and bookmark this page and if any issues occur , please click on this link and run the McAfee subscription repair tool that should fix your issue.
OK, it didn't automatically pick up the 2012 dates after my 2011 expired. When you mentioned to run the repair tool, is that the only thing I have to do - OR - do I have to go through the steps of renaming current data files, etc? Why can't I go in and remove the 2011 from my account - the 2012 was supposed to have done that already......
You might run into different kinds of complications if you have 2 program activated in your PC at the same time. It would be better to uninstall the older version first.