problem with arel

[francescoagati]

with arel 2.0.8 tramp try to load version 0.4.0 with this error

ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/table.rb:38:in table_exists?': undefined methodtable_exists?' for #Tramp::Engine:0x12b1a00 (NoMethodError)
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/table.rb:44:in attributes' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/relation.rb:46:inselect_clauses'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/compiler.rb:75:in method_missing' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/compiler.rb:12:inselect_sql'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/arel-0.4.0/lib/arel/engines/sql/relations/relation.rb:14:in to_sql' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/engine.rb:21:inread'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/arel_monkey_patches.rb:22:in call' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/arel_monkey_patches.rb:7:inread'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/arel_monkey_patches.rb:26:in all' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/relation.rb:20:inall'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/tramp-0.2/lib/tramp/finders.rb:4:in all' from tramp.rb:15:inblock in

'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/eventmachine-1.0.0.beta.2/lib/eventmachine.rb:197:in call' from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/eventmachine-1.0.0.beta.2/lib/eventmachine.rb:197:inrun_machine'
from /Users/Francesco/.rvm/gems/ruby-1.9.2-p0/gems/eventmachine-1.0.0.beta.2/lib/eventmachine.rb:197:in `run'

this is the code i try:

Tramp.init......

class Book < Tramp::Base

attribute :ID, :type => Integer, :primary_key => true
attribute :Title_IT
end

EM.run do

Book.all {|book| p book.inspect; EM.stop}

end