Problem:

When a Visual Basic program creates another VB object and attempts to pass this object to a Cobol Object the the Build Error "Reference required to assembly 'xxx' containing the type 'xxx.yyy'. Add one to the project. The calling project does have all the required references.

The error occured in Visual Studio 2003.

Resolution:

This is caused by a bug in VB and is documented by Microsoft at:

http://support.microsoft.com/kb/818411

To work around the problem by adding a reference to the Assembly DLL rather than the project.

This error was also resolved in Visual Studio 2005.