[TIMOB-541] Problem using umlaut as row-title

Hello,

when trying to build a grouped table-view on iPhone my application throws the exception

iPhone Simulator 3.1 (139.1), iPhone OS 3.1 (7C144)
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: ' -[NSCFString appendString:]: nil argument'

The crash seems to be triggered by the umlaut "ß" (html-encoded: ß).

Code for reproduction (just create a new project and insert into app.js):

Titanium.UI.setBackgroundColor('#000');

var window = Titanium.UI.createWindow({  
    title:'Window',
    backgroundColor:'#fff'
});

var tableData = [];

var section = Ti.UI.createTableViewSection();
section.headerTitle = 'SectionHeader';

var umlautRow = Ti.UI.createTableViewRow({title:'Umlaut ß'});
section.add(umlautRow);

tableData.push(section);

var table = Ti.UI.createTableView({
    data:tableData,
    style:Titanium.UI.iPhone.TableViewStyle.GROUPED
});

window.add(table);

window.open();

Using Titanium Mobile v1.0 / OSX 10.5.8 / iPhone SDK 3.1 and 3.1.2.

Got no idea on how to fix this myself, so any help would be greatly appreciated.