I've worked through the jump start and am now trying a simple windows project on my own and have quickly run into a problem with MM 2.1

I created a set of business objects and put them into their own solution (My Project Business), I then created a windows project (My Project) and added a maintenace form for for one of the objects, call it Foo. When I try to run it I get an error message: Could not load type 'MyNamespace.Business.Foo' from assembly 'My Project, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. Note: Foo is in the My Project Business assembly - the reference exists and eveything compiles OK.

The error occurs immediately in the mmAppDesktop.FormMgr.ShowDialog() call (right after it retreives the formmgr property. The first line of code in the maintenance form constructor is a call to InitializeComponent(). A breakpoint here is never reached. the next line registers the business object. Oddly, if that line is commented out, the form runs...

I cannot instantiate a Foo object on the Object Test Bench from the main project. I instantiate the AAppTest object and then, when I try to instantiate the Foo object, I get a dialog saying that "The project needs to be rebuilt" - no matter how many time I rebuild it. I can instantiate and exercise the Foo object if I load only the Business Object solution into VS.

I expect I've made a really dumb beginner's error, but I can't figure it out. Help please.