Odd problem with decimal PKs and validation failures in ActiveRecord's save! on JRuby

.gitignore

Gemfile.lock
*.sqlite3

bizarre-jruby-ar.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'active_record'

ActiveRecord::Base.establish_connection(
  :database => 'people.sqlite3',
  :adapter => RUBY_PLATFORM == 'java' ? 'jdbcsqlite3' : 'sqlite3'
)

ActiveRecord::Schema.create_table('people',
  :id => false,
  :force => true
) do |t|
  t.decimal :id, :primary_key => true
  t.string :username
end

ActiveRecord::Base.connection.execute(
  "INSERT INTO people (id, username) VALUES (1.0, 'jo')")

class Person < ActiveRecord::Base
  validate :validate_fail

  def validate_fail
    errors.add(:username, "no good")
  end
end

p = Person.find_by_username 'jo'

# This block throws the expected exception on MRI 1.8 and 1.9, but 
# throws a NoMethodError referencing "coerce" on TrueClass on JRuby.
begin
  p.save!
rescue ActiveRecord::RecordInvalid => e
  puts "Validation aborted save as expected.\n  #{e.class}: #{e}"
end

Gemfile

source :rubygems

gem 'activerecord', '2.3.10'

platform :jruby do
  gem 'activerecord-jdbcsqlite3-adapter'
end

platform :ruby_18, :ruby_19 do
  gem 'sqlite3'
end

Output on JRuby 1.5.6:
-- create_table("people", {:id=>false, :force=>true})
-> 0.1080s
-> 0 rows
/Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/base.rb:2981:in convert_number_column_value': undefined methodcoerce' for true:TrueClass (NoMethodError)
from /Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/attribute_methods.rb:311:in write_attribute' from /Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/dirty.rb:139:inwrite_attribute_with_dirty'
from /Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/base.rb:2551:in id=' from /Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/transactions.rb:212:inrollback_active_record_state!'
from /Users/rsutphin/.rvm/gems/jruby-1.5.6@bcsec/gems/activerecord-2.3.10/lib/active_record/transactions.rb:200:in `save_with_transactions!'
from bizarre-jruby-ar.rb:35

The output on ruby 1.8 and 1.9 is as expected.

Output on JRuby 1.6.0.RC1:

$ ruby bizarre-jruby-ar.rb 
-- create_table("people", {:id=>false, :force=>true})
   -> 0.1110s
   -> 0 rows
org/jruby/RubyBigDecimal.java:821:in `eql_p': undefined method `coerce' for true:TrueClass (NoMethodError)
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/base.rb:2981:in `convert_number_column_value'
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/attribute_methods.rb:311:in `write_attribute'
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/dirty.rb:139:in `write_attribute_with_dirty'
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/base.rb:2551:in `id='
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/transactions.rb:212:in `rollback_active_record_state!'
    from /Users/rsutphin/.rvm/gems/jruby-1.6.0.RC1@tmp/gems/activerecord-2.3.10/lib/active_record/transactions.rb:200:in `save_with_transactions!'
    from bizarre-jruby-ar.rb:35:in `__file__'