Phonegap Cordova FileSystem not persistent on iOS? - ios

Question

I am working on an app for iOS and Android, and I am using Cordovas File plugin to save some data to a file on the device.
This file will contain information about the user, so he/she does not have to log in every time they use the app, so the information has to be there even if the app is exited and relaunched.
On Android this works fine:
window.requestFileSystem(LocalFileSystem.PERSISTENT, 20*1024*1024, app.onFileSystemSuccess, fail);
On Android the data I save is there next time I open the app, but on iOS the file is empty (or not existing).
Does this not work for iOS?
Here is the whole source:
var app = {
initialize: function()
{
this.bindEvents();
},
bindEvents: function()
{
document.addEventListener('deviceready', this.onDeviceReady, false);
},
onDeviceReady: function()
{
app.initAPP();
},
initAPP: function()
{
window.requestFileSystem(LocalFileSystem.PERSISTENT, 20*1024*1024, app.onFileSystemSuccess, fail);
},
onFileSystemSuccess: function(FS)
{
FS.root.getDirectory('MyAPPDir', {create:true}, app.gotDir, fail);
},
gotDir: function(Dir)
{
app.appRoot = Dir;
try{
app.appRoot.getFile('authInfo.txt', {create:true}, function(fileEntry){
fileEntry.file(function(file){
alert('Got file authInfo.txt')
var Reader = new FileReader();
Reader.onloadend = function(e){
alert(e.target.result);
if( e.target.result == '' ){
$('#container').load('login.html');
}
else{
document.authInfo = e.target.result;
alert(e.target.result);
alert('You are now auhtorized');
}
}
Reader.readAsText(file);
})
})
} catch(e){
$('#container').load('login.html');
}
},
authUser: function()
{
email = $("#email").val();
password = $("#password").val();
$.ajax({
url: AUTH_URL,
type: 'POST',
data:{
email: email,
password: password
},
success: function(data){
resp = $.parseJSON(data);
if( resp.status == 'success' ){
try{
app.appRoot.getFile('authInfo.txt', {create:true}, function(fileEntry){
fileEntry.createWriter(function(writer){
writer.truncate(0);
writer.onwriteend = function(){
writer.write(resp);
writer.onwriteend = function(){
alert('Wrote '+JSON.stringify(resp)+' to '+fileEntry.toURL());
}
}
});
});
}
catch (e){
alert(e);
}
} else {
alert(resp.message);
}
}
});
}
};
function fail(a){
alert(a);
}
I get this message in iOS:
Wrote {.......myjson.....} to cdvfile://localhost/persistent/MyAPPDir/authInfo.txt
But then when it tries to read it on launch it seems like the file does'nt exist any more, or is empty?