The unfortunate reality is that the set of IActiveScript interfaces that Chakra exposes is not intended for public consumption. (The GUID isn't published into the registry for exactly that reason.) Chakra only implements that portion of the IActiveScript interfaces needed to support Internet Explorer and the Visual Studio editor/debugger, and no effort has been made to ensure the completeness or correctness of the interfaces beyond that which those two clients use.
It looks like your scenario is one of those that's not implemented to spec, probably because IE/VS doesn't use the interface in this particular way. Sadly, there's almost no chance this would be fixed unless there is a decision to publicly support the IActiveScript interfaces in some future version of IE.
IE11 has introduced a public API for Chakra, but it is not IActiveScript-based, it's Win32-based. You can get more details here: http://www.panopticoncentral.net/2013/07/02/introducing-jsrt-embedding-javascript-on-windows/. I have no idea if that would help you in your situation or not.
Sorry, not the answer you were hoping for, I'm sure...