This is what I did and it worked. Please try if you want. As I say to all my clients, always take a backup before doing any changes or update son your hosting.
What you need to do downloaded the latest version to your computer, go into your hosting account and then upload the zip file to the plugins directory. Remove the other adrotator plugin folder, unzip the new one and then delete your add you are trying to place and then re create it and it should have the correct date now.