Using COM interface obtained from local server

Hi.

My client code used to obtain and use interfaces from an inproc
server. Here is an example (without error checking):

void ClientFunc()
{
    CComPtr<IBookStore> bookStore;
    CComPtr<IBookCollection> bookCollection;
    CComPtr<IBook> book;

    bookStore.CoCreateInstance(L"BookStore.Bookstore");
    bookStore->getCollection(&bookCollection);
    bookCollection->find(L"D. Box", &book);

    // Using 'book'
    .............

}

Everything works ok with that.

Now I need to obtain the 'IBookCollection' interface from a local
server, which is realized as a windows service. In that server I've
declared and realized a small interface, which contains
'getBookCollection' among some other functions. It mainly does the
same as the above client function and returns a pointer to interface
'IBookCollection':

STDMETHODIMP CoBookManager::getBookCollection(IBookCollection**
ppIBCol)
{
    m_bookCollection.Release();
    m_bookStore->getCollection(&m_bookCollection);

    *ppIBCol = m_bookCollection;
    (*ppIBCol)->AddRef();

    return NOERROR;

}

Now the client code doesn't work as is supposed to with the
interface,
returned from the local server. I've properly declared IBookManager
interface in the IDL file, and expected, that everything would be ok
with IBookCollection interface marshalling, but seems, something is
wrong. I haven't used COM components resided in other processes.
Please help, what am I doing wrong?

Thanks,
Martin