Configuration changes needed for running SSIS 2008/2008 R2 classes in .NET4.0

Recently we came across a case where the customer was developing a .NET managed application using SQL Server Integration Services (SSIS) object model.  The managed application was behaving differently in different versions of Visual Studio (2008 vs 2010). We finally figured out the whys. Rather than let the good research go to waste, we’re posting…