DI API .dll problem when using .NET setup wizard

Hi.

I'm trying to create an application which will not be installed as an add-on in SBO. I want the application to use windows forms and connect to SBO with the DI API 2005 dll. The project works fine when i run the application. When i try to build a Setup.msi project i get the following error <b>Could not find file 'C:\path\project\obj\Interop.SAPbobsCOM.dll' 'Interface not registered'</b>

I have re-included the <b>SAPbobsCOM.dll</b> component thinking that the file might have been corrupted but this still did not fix the problem.

I'm using the .NET 2003 IDE and SAPbobsCOM 2005 DI API Component.