title: arc4random always returns same initial value on app start
body: <p>I am developing an application for the iphone that, in viewDidLoad, calls arc4random to get a random number.  My problem is that each time the application starts, it gets the same number from arc4random.  I ought to point out that I see this behaviour when I test the app on my iphone device and start the application from the device touchscreen.  If I run the app on the device from xcode, then I see different random numbers.</p>
  
  <p>Any help or advice would be appreciated.  Thanks.</p>