Rails: Some seeds don't appear to be saving - ruby-on-rails

Question

It appears some of my seeds are not saving. For starters, I will show a console session so you can see that the 'instructor_id' is indeed being set in the console, but not when I seed.
ruby-1.9.2-p180 :015 > c = Course.find 2
Course Load (1.6ms) SELECT "courses".* FROM "courses" WHERE "courses"."id" = $1 LIMIT 1 [["id", 2]]
=> #<Course id: 2, name: "Microcomputers II Lab", course_code: "CE-420L", instructor_id: nil, school_id: nil, created_at: "2011-06-04 19:40:32", updated_at: "2011-06-04 19:40:32">
ruby-1.9.2-p180 :016 > c.instructor = Instructor.first
Instructor Load (0.6ms) SELECT "instructors".* FROM "instructors" LIMIT 1
=> #<Instructor id: 1, name: "Instructor Name", created_at: "2011-06-04 19:40:32", updated_at: "2011-06-04 19:40:32">
ruby-1.9.2-p180 :017 > c
=> #<Course id: 2, name: "Microcomputers II Lab", course_code: "CE-420L", instructor_id: 1, school_id: nil, created_at: "2011-06-04 19:40:32", updated_at: "2011-06-04 19:40:32">
From looking at the console, you can see that when I call c.instructor = Instructor.first, it is correctly setting my instructor_id.
Now, in the seeds file I have variables. (This is just a snippet)
### Instructors ###
puts "Creating Instructors"
instructor_1 = Instructor.find_or_create_by_name("Instructor Name")
### Courses ###
puts "Creating Courses"
ce420L = Course.find_or_create_by_name("Microcomputers II Lab", :course_code => "CE-420L")
### Add the Instructor to the Course ###
puts "Adding an Instructor to the Courses"
ce420L.instructor = instructor_1
But when I run the seeds using 'rake db:seed', it is correctly creating all of my models, and most of my relationships. But it is not setting the instructor properly.
Thoughts?
EDIT:
Just tried:
ce420 = Course.find_or_initialize_by_name("Microcomputers II")
ce420.instructor_id = instructor_1.id
ce420.save!
And it did not save my instructor.
Here are my models.
class Instructor < ActiveRecord::Base
### ASSOCIATIONS ###
has_many :courses
end
class Course < ActiveRecord::Base
belongs_to :instructor
end

Answer 1

Did you run...
ce420L.save!
... after assigning the instructor?

Answer 2

Much faster to do this:
### Courses ###
puts "Creating Courses belonging to Instructor 1"
ce420L = Course.find_or_initialize_by_name("Microcomputers II Lab") :course_code => "CE-420L")
ce420L.instructor_id = instructor_1.id
ce420L.save
Note the following:
You had an errant comma after your find_or_create on ce420L.
Doing the assignment together with the course creation prevents the system from validating and saving ce420L twice.
You can try assigning the specific ID as I did, i.e. ce420L.instructor_id = ...
If this doesn't work, check your Instructor Model to ensure you don't have any callbacks getting in the way.