Big thanks to np83 not only for finding this bug but also posting a fix and unit tests.

This projects contains many of the examples upload on my blog.
Each time docx is released, I will update these examples so as they still work regardless of API changes.

2) Gave UnitTests internal access to DocX.dll 
DocX AssemblyInfo.cs
[assembly: InternalsVisibleTo("UnitTests")]

3) Updated target framework to .NET 4.0.

4) Fixed bug with InsertText() Formatting object was set to null by default, should have been new Formatting()

// Create a new document.
using (DocX document = DocX.Create(@"C:\Users\Cathal\Desktop\Hello.docx"))
{
    // Set this documents orientation to landscape and save.
    document.PageLayout.Orientation = Orientation.Landscape;
    document.SaveAs(@"Landscape.docx");

    // Set this documents orientation to portrait and save.
    document.PageLayout.Orientation = Orientation.Portrait;
    document.SaveAs(@"Portrait.docx");
}

Added bug fix for RemoveText when index is greater than possible.
Removed a few function overloads by utilising .NET 4.0 optional parameters.

Added unit tests for Paragraph.RemoveHyperlink(int index)

    runLookup
    BuildRunLookup();

Added new unit tests for Paragraph.InsertHyperlink()

Added getter and setter of document core properties for DocX.
Added unit test for ApplyTemplate.