User blog comment:Isabella and Lego Liker/3.812 million played "Skiddley Whiffers"!/@comment-5522044-20110830033808/@comment-406459-20110830044222

It's not really a lack of viewers- the 4 million area is standard fare. "Tour de Ferb" got 3.9 million, for example. Most recent episodes seem to have been getting an over/under of 4 million- which seems to show that though Irene may have given some a loss of power, it still couldn't keep people away from Phineas and Ferb.