[TIMOB-520] scroll view + vertical layout not working

here's a test case:

var win = Ti.UI.createWindow({

backgroundColor:'#336699'

});

var scrollView = Ti.UI.createScrollView({

contentHeight:'auto',
layout:'vertical',
width:300,
borderRadius:10,
backgroundColor:'#fff'

});

var view1 = Ti.UI.createView({

height:250,
top:10,
width:300,
backgroundColor:'orange'

});

scrollView.add(view1);

var view2 = Ti.UI.createView({

height:250,
top:10,
width:300,
backgroundColor:'red'

});

scrollView.add(view2);

var view3 = Ti.UI.createView({

height:250,
top:10,
width:300,
backgroundColor:'green'

});

scrollView.add(view3);

win.add(scrollView);

win.open();