XmlSerialization doesn't write to file

[Erendar]

Personally i'm using the TextWriter version

if (FileList.myFiles[0].Count > 0 && Global.bSerialEnable)
                    {
                        foreach (long key in FileList.myFiles[0].Keys)
                        {
                            tempdataitems.Add(new DataItem(key.ToString(), FileList.myFiles[0][key].ToString()));
                        }

                        XmlSerializer serializer = new XmlSerializer(typeof(List<DataItem>));
                        StringWriter sw = new StringWriter();
                        XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
                        ns.Add("", "");

                        serializer.Serialize(sw, tempdataitems, ns);
                        string path = sMyPath + @"\data.bin";
                        File.WriteAllText(path, sw.ToString(), Encoding.Unicode);
                        sw.Dispose();
                    }

Where DataItem is this (only used for serialization)

public class DataItem 
    {

        public string Key;

        public string Value;

        public DataItem(string key, string value)
        {
            Key = key;
            Value = value;
        }
        public DataItem()
        {

        }
    }

FileList is a personnal class. sMyPath is my application path