To get around the issues described in the box called "Data Integrity in Development", run the following at the console:

s = Story.find(:all)
s.each do |x|
x.user_id = 1
If you don't have a User with a user_id of 1, edit as required.

Will be obvious to old-timers, but I was pleased to find my own user for Ruby's Blocks. Maybe it'll help someone else.