Schedule Slip: An extremely rare occurrence. More prone to the inversion so getting published on a more rapid rate. The Zombie Halloween arc of 2011 holds the record with 2 pages/day! Still suffered a smaller Series Hiatus in the summer of 2013 because of the author's health problems.
To elaborate: This goes both ways so Roommates and Word Of Ashe is Word of Saint Paul for GND. The two authors actively try to build on the other's work, and incorporate as much as they can from the other's canon.