保存XML文件时出错

我有一段C#代码，它将Itunes当前播放的曲目信息保存到XML文件中。这段代码有时运行良好，但通常会在myXmlDocument.Save（ClsUtils.XmlPath）上显示错误"进程无法访问xml文件，因为它正被另一个进程c#使用"；

有人能指出这里可能出了什么问题吗。。。。。

以下是代码

public void ModifyLastTrack(bool bOnlyPlayerPosition)
    {
        //initilize XML Document
        XmlDocument myXmlDocument = new XmlDocument();
        //load Xml into document
        myXmlDocument.Load(ClsUtils.XmlPath);
        //get Node for modify if Checked state Changed
        XmlNode DictLastTrackNode;
        DictLastTrackNode = myXmlDocument.DocumentElement;
        foreach (XmlNode ChildDictNode1 in DictLastTrackNode.ChildNodes)
        {
            foreach (XmlNode ChildDictNode2 in ChildDictNode1.ChildNodes)
            {
                if (!bOnlyPlayerPosition)
                {
                    if (ChildDictNode2.Name == "TrackID")
                        ChildDictNode2.InnerText = TrackID;
                                       }
                else
                {
                    if (ChildDictNode2.Name == "PlayerPosition")
                        ChildDictNode2.InnerText = PlayerPosition.ToString();
                }
            }
        }

        //save Xml after modification
        myXmlDocument.Save(ClsUtils.XmlPath);
    }

 string fileName = @"D:'pathname.jpg";//Path to locked file
Process Handletool = new Process();
Handletool.StartInfo.FileName = "handle.exe";
Handletool.StartInfo.Arguments = fileName+" /accepteula";
Handletool.StartInfo.UseShellExecute = false;
Handletool.StartInfo.RedirectStandardOutput = true;
Handletool.Start();           
Handletool.WaitForExit();
string outputTool = Handletool.StandardOutput.ReadToEnd();
string matchPattern = @"(?<='s+pid:'s+)'b('d+)'b(?='s+)";
foreach(Match match in Regex.Matches(outputTool, matchPattern))
{
    Process.GetProcessById(int.Parse(match.Value)).Kill();
}