AtlMarshalPtrInProc return E_NOINTERFACE

Hello,

I've ran into some problem I do not understand. Can anyone please enlighten
me by telling what I am doing wrong?

I have 3 interfaces in my IDL file

///// aaa.idl

[
    object,
    uuid(uid_1),
    pointer_default(unique)
]
interface IA : IUnknown{
 .........
// methods
}

[
    object,
    uuid(uid_2),
    pointer_default(unique)
]
interface IB : IUnknown{
 .........
// methods
}

[
    object,
    uuid(uid_3),
    pointer_default(unique)
]
interface IC : IUnknown{
 .........
// methods
}

I also have c++ class

class ATL_NO_VTABLE CMyClass :
    public CComObjectRootEx<CComGlobalsThreadModel>,
    public CComCoClass<CMyClass , &CLSID_MyClass>,
    public IA,
    public IB,
    public IC
{
    // class methods etc
}

Somewhere in my project I have the following code

    CComObject<CMyClass> *p;
    CComPtr<IA> pp;
    IStream *pStm;

    HRCHECK( CComObject<CMyClass>::CreateInstance(&p));
    HRCHECK(p->QueryInterface(IID_IUnknown, (void**)&pp));

    HRESULT hRes = AtlMarshalPtrInProc(pp, IID_IB
                    &pStm);

AtlMarshalPtrInProc works just fine if I try to marshal pp as IID_IA or
IID_IC but fails with E_NOINTERFACE if I try to marshal it as IID_IB. What
am I doing wrong here?

Thanks in advance