It seems to happen every couple years
Time got away from me and I realized today that I missed posting a book of the week for the last 2 weeks. There is a book posted for this week (#46), but week #44 and week #45 had no books posted. After a slow start in 2007 I missed 2 weeks in 2009. As it has happened again in 2011 I clearly need to be careful in 2013.