This RubyMotion project shows an iPad app that doesn't seem to respond to upside down orientation. To build just: rake device_family=ipad

orientation_issue.rb

module Orientation
  def ipad?
    UIDevice.currentDevice.userInterfaceIdiom == UIUserInterfaceIdiomPad
  end
end  

class AppDelegate
  include Orientation
  
  def application(application, didFinishLaunchingWithOptions:launchOptions)
    @window = window
    @window.makeKeyAndVisible
    true
  end
  
  def window
    @window ||= begin
      w = UIWindow.alloc.initWithFrame UIScreen.mainScreen.bounds
      if ipad?
         w.rootViewController = MainView.alloc.initWithText "Demo iPad"
      else
        w.rootViewController = MainView.alloc.initWithText "Demo iPhone"
      end
      w
    end
  end
  
end

class MyUIViewController < UIViewController
  include Orientation
  
  def willRotateToInterfaceOrientation(orientation, duration:duration)
    super
    puts "willRotateToInterfaceOrientation #{orientation}"
    puts "device is ipad: #{ipad?} comparing orientation #{orientation} against upside-down #{UIInterfaceOrientationPortraitUpsideDown}"
    result = true if ipad? or
      orientation != UIInterfaceOrientationPortraitUpsideDown
    puts "calculated #{result}"
    result
  end
end

class MainView < MyUIViewController
  def initWithText(text)
    initWithNibName nil, bundle:nil
    @text = text
    self
  end
  
  def viewDidAppear(animated)
    super
    self.view.backgroundColor = UIColor.whiteColor
    @label ||= UILabel.alloc.initWithFrame [[10, 10], [100, 100]]
    @label.text = @text
    self.view.addSubview @label
  end
  
  def willRotateToInterfaceOrientation(orientation, duration:duration)
    self.view.setNeedsLayout if super
  end
end

Rakefile

# -*- coding: utf-8 -*-
$:.unshift("/Library/RubyMotion/lib")
require 'motion/project'

Motion::Project::App.setup do |app|
  # Use `rake config' to see complete project settings.
  app.name = 'foo'
  app.device_family = [:iphone, :ipad]
  interface_orientations = [:portrait, :landscape_left, :landscape_right, :portrait_upside_down]
end