One problem related to power door locks not working has been reported for the 2011 Toyota Prius. The most recently reported issues are listed below.
Driver side door lock failed and shortly thereafter the front passenger door lock also failed. We have owned a total of five Prius vehicles since 2007 and have never experienced this problem before this dual failure. Judging from the number of complaints on this site and info gathered during internet research it appears this is a widespread problem, most likely due to poor quality or defective door lock actuators. A google search (Toyota Prius "door lock" failure) resulted in a quarter million results.