[TIMOB-1843] ipad grouped tableview does not allow window background image

on 1.4.1 with iOS sdk 3.2 when a grouped table is used the underlying window's background image is not shown or is barely shown.

var win = Ti.UI.currentWindow;

var data = [];

for (var c=0;c<4;c++)
{

data[c] = Ti.UI.createTableViewSection({headerTitle:'Group '+(c+1)});
for (var x=0;x<10;x++)
{
    data[c].add(Ti.UI.createTableViewRow({title:'Group '+(c+1)+', Row '+(x+1),backgroundColor:'#FF0000'}));
}

}

// create table view var tableview = Titanium.UI.createTableView({

data:data,
style: Titanium.UI.iPhone.TableViewStyle.GROUPED,
backgroundColor:'transparent'

});

// create table view event listener tableview.addEventListener('click', function(e)
{

// event data
var index = e.index;
var section = e.section;
var row = e.row;
var rowdata = e.rowData;
if (section.headerTitle.indexOf('clicked')==-1)
{
    section.headerTitle = section.headerTitle + ' (clicked)';
}
Titanium.UI.createAlertDialog({title:'Table View',message:'row ' + row + ' index ' + index + ' section ' + section  + ' row data ' + rowdata}).show();

});

// add table view to the window Titanium.UI.currentWindow.add(tableview);