#1 - Oct. 15, 2010, 6:19 a.m.
So glad you asked beforehand, Lesedi :)
This can indeed be an issue with mobiles, if the app gets wiped.
What you want to do in this case is first, take the authenticator off your account (very temporarily) through Account Management.
Immediately upgrade as you need to - then reinstall the authenticator and readd it to your account.
That will then use your new serial number (which reinstalling the app will give you) and everything should be good!