Today, Sept 18th, is the day you need to setup AdSense manually for the Rubicon Project, if you use AdSense through Rubicon. Prior to today you could have Google AdSense in the mix of the networks they optimized without needing to create an AdSense account, and without needing to create individual AdSense tags which then need to be provided to Rubicon. However as of today you need to do just that, you should have received an email from Rubicon with step by step instructions. If not let me know and I can paste it here.