Variable area in blocks

David A. Black (The Well Grounded Rubyist, chapter 6) presents the following code:

def block_local_parameter
  x = 100
  [1,2,3].each do |x|
    puts "Parameter x is #{x}"
    x += 10
    puts "Reassigned to x in block; it is now #{x}"
  end
  puts "The value of outer x is now #{x}"
end

block_local_parameter

The expected result according to the book (Ruby 1.9.1):

Parameter x is 1
Reassigned to x in block; it now 11
Parameter x is 2
Reassigned to x in block; it now 12
Parameter x is 3
Reassigned to x in block; it now 13
Outer x is still 100

My conclusion (Ruby 1.8.7):

Parameter x is 1
Reassigned to x in block; it now 11
Parameter x is 2
Reassigned to x in block; it now 12
Parameter x is 3
Reassigned to x in block; it now 13
Outer x is still 13

Is the book wrong? Or am I missing something?