PayPal announced a change in their IPN and PDT API a while back. This change is suppose to take effect from the 1st February 2013. More details on this announcement and the required changes can be found at the following link:
What does it mean for you?
We are on top of things as usual :) so you don't need to worry about this PayPal change too much.
All of our plugins were updated to work with the changes that PayPal is making. We did the changes a while back so you shouldn't need to change or do anything.
If you are paranoid about it or having an issue regarding PayPal IPN or PDT validation, simply download a new version of the plugin from our server and update your copy of the plugin now and you are good to go.