Remoting Passing objects

[ropo]

I'm creating 2 objects on a server from a remote client then calling a
function on one object passing the other as an argument to this. This
results in a Load lock exception. All objects are marshalbyref.

Does anyone know why this happens and what I can do about it?

here is the code outline

// shared interfaces C#.NET
interface A
{
B CreateB()
C CreateC()
}

interface B
{
void foo(C);
}

interface C
{
// some properties

}

// on the server C++.NET
class Aclass : public MarshalObjectByRef, public A
{
public:
virtual B CreateB() = A::CreateB { return (B)gcnew Bclass(); }
virtual C CreateC() = A::CreateC { return (C)gcnew Cclass(); }
};

class Bclass : public MarshalObjectByRef, public B
{
public:
virtual void foo(C obj) = B::foo { return; }
};

class Cclass : public MarshalObjectByRef, public c
{
// ...

};

// on the remote client C#.NET
B Bobj = A.CreateB();
C Cobj = A.CreateC();

// this works
Bobj.foo(null);

// this produces a load lock exception
Bobj.foo(Cobj);