New Post: Newb questions

Hello

As a newcomer to this project I have some very fundamental questions. I use NPOI version 2.0 RC and have also downloaded source code version 2.0.6RC1

0- My most intensive problem right now is that WorkBook.GetSheetAt(i).TabColorIndex returns null reference exception. Although learning the basics is important for me, before that I need to proceed with my project and overcome this obstacle.

1- What is the usage of different namesapces DDF, HPSF, HSSF, POISF, SS, Util? I can't find any reference about them.

2- I've read somewhere on net about namespace XSSF (xlsx files) but it is not included in my project. where ca I get it?

3- Why HSSFWorkbook returns sheets of type ISheet? how is it to get HSSFSheet? or if it is not possible to get it, why is it here? Is there any third or even fourth parallel object model?

4- Could you please help how to include source code in a project instead of binaries? which files shall be copied to project? Is source code version 2.0.6RC1 an stable version?

This many of questions is only because I can't find correct reference document. I wish I could find it and ask less questions!

Thanks in advance