title: opengles view switching problem
body: <p>I´m trying to make simple game using OpenGLES.
  I have two EAGLViews(menu and game view).
  Each view has its own viewController. Initializing of the views is done by initWithNIBName method of the viewController. 
  And when I want to show the view, I simply use addSubview method of the main window.
  The game view is initialized only once at the launch time. Menu view is initialized only if it´s needed. Problem is, that when I go from game view to menu and then back, and then I redraw the game view, something goes wrong. (I'm setting EAGLContext in drawView method before drawing, so the context may be right). 
  Don´t you know where is the problem?
  Or if the whole switching is managed wrong, gimme and advice please.
  Thanks for replies. </p>