Any help would be appreciated for the following problem. I've already
spent a day at this, and enough is enough.

I'm writing a ORM program. and in the process of running it against a
database, I'm creating dozens of classes. I want to insert these
classes into the .csproj file automatically. I can do it just fine
manually, and I can do it also programatically up to the point that I
save the XmlDocument object. At that point, for some Redmond reason,
the XmlDocument.Save method insists on writing an xmlns="" attribute
to the node. This causes Visual Studio to puke upon trying to load the
project.

Here's the code that I use to add the node programatically

   public Form1()
   {
    InitializeComponent();
   
    XmlDocument doc = new XmlDocument();
    string filename =
@"e:\Projects.NET\BB\BusinessBuilder.csproj";
    doc.Load(filename);
    XmlNode currentnode = doc.DocumentElement.FirstChild;
    Boolean test = false;
    do
    {
        currentnode = currentnode.NextSibling;
        if (currentnode == null)
            break;
        if (currentnode.Name == "ItemGroup" &&
currentnode.FirstChild.Name == "Compile")
            test = true;
    } while (test == false);
    if (test == true)
    {
        XmlElement elem = doc.CreateElement("Compile");
        XmlAttribute att = doc.CreateAttribute("Include");
        att.Value = @"DAL\test.cs";
        elem.Attributes.Append(att);
        currentnode.AppendChild(elem);
    }
    doc.Save(filename);
   }

after the program runs, here is the line that it has inserted (in the
proper place)

   <Compile Include="DAL\test.cs" xmlns="" />

and here is the error message that I receive when I try to load the
project

    Unable to read the project file 'BusinessBuilder.csproj',
    E:\Projects.NET\BB\BusinessBuilder.csproj (105,5):
    The element <Compile> beneath element <ItemGroup> may
    not have a custom XML namespace.

If I remove the xmlns="" manually, the project then opens fine.

All I can assume from my testing is that Microsoft must have something
else it uses to write to this file, since they apparently have no
problem doing the same thing if I add the class through the Solution
Explorer. If I can't get an answer, I'm going to be forced to treat
this thing as a plain text file, and add the lines in that way. That's
a hell of a way to deal with 'state-of-the-art' technology.

At any rate, any help would be appreciated. TIA.