I am not sure if there is anything else you are missing.  I attached two screen shots.  You will see in the second one how I scrolled all the way to the right, but unlike you, I don't see the last column "Reports To".

Could this be a browser issue?  DOCTYPE?  HTML/CSS?  Environment?

I can't seem to reproduce the issue in the Sample Project even after I added and simulated my project code step by step in the Sample Project!

Some of the main differences in both projects are:

SampleProject:
1. Uses App_Code and App_Data. 
2. Reference to the WebGrid.dll only

My Project:
1. Doesn't use App_Code and App_Data.  Instead, I have different projects in the solution (Business Logic Layer Project, Data Access Layer Project, etc..) 
2. References to WebGrid.dll, ISChartEngine.dll, WebDesktop.dll, Resources.dll, ActiveReports.Exporting.dll. 

Do you think this has any effect?

Hi Yudi,

Of course your sample code works smoothly.  So I created a project, the code and steps of how I load and manipulate the grid and columns are similar to what I do in my project.

Thanks again for your assistance!