Relationships across Projects

Hi,

I am using SDE Pro for VS.Net and have the following problem.

I have a diagram for Project1 with class A. Class A uses Class B in Project 2 and I would like to show this in a diagram created in Project 1.

Problem is, I cannot drag Class B in Project 2 to the diagram created in Project 1.

This is a basic feature that is supported in almost all standalone modelers. Is this a limitation to the intregated modeler or is there a way to accomplish this?

Many thanks,
charlie