Okay so actually seem to have only have one license, the license you purchased in 2010 with megdarnell email address, when the license is created it includes the encoded email address as part of the license, so we cant modify the email without changing the license. But we did add support to associate a second email with the license so meglmt email address is now associated with the license, so if you make payment and the payment is linked to either address it will update the correct original license.
But the email address shown on the title bar is still the original email, we do have an issue open that would change to show the current email instead of original email https://jthink.atlassian.net/browse/JAIKOZ-1227 but it isnt done yet.
So I dont really see a problem here, you dont need to use your old email address for purchases so it doesnt matter that license was originally linked to it. If you really want your new email address displayed title bar then you have two choices, wait for the fix to be done, or purchase another license.