[TIMOB-11300] iOS: Grouped tableview background color not behaving as expected

When using a grouped tableview with "style: Titanium.UI.iPhone.TableViewStyle.GROUPED", the background color of the tableview is not behaving as expected. When using the default settings (with no color set) it is expected that all iOS versions show the "striped" background. This is not the case with iOS 6, it seems a transparent background is used. Additionally, when setting a background color, the tableview rows also adopt this color, this occurs on all iOS versions tested (iOS 4.3.5, 5.1, 6.0). This is a regression as it does not occur in 2.1.2GA (unable to test on device)

var win = Ti.UI.createWindow();

var data = [
		{title:'Row 1', hasChild:true, color:'red', selectedColor:'#fff'},
		{title:'Row 2', hasDetail:true, color:'green', selectedColor:'#fff'},
		{title:'Row 3', hasCheck:true, color:'blue', selectedColor:'#fff'},
		{title:'Row 4', color:'orange', selectedColor:'#fff'}
	];
	
var tableview = Titanium.UI.createTableView({
		data:data,
		style: Titanium.UI.iPhone.TableViewStyle.GROUPED//,
		//backgroundColor: "red"
	});
	
win.add(tableview);
win.open();

Steps to reproduce: part one: 1) Create a project with the sample code above 2) Run in iOS 6 simulator or on device part two: 1) Uncomment background color and comma in code 2) Run in simulator or on device Results: part one: iOS 6: Transparent background iOS <6: Striped background Part two: Tableview and tableview rows show red color