Debugging a C++/CLI child process

OS = Windows 7
IDE = Visual Studio 2012 update 4

Hi,
I have a 32-bit native C++ application that spawns a 32-bit native C++ child process. I have always been able to debug into both processes without issue. I have just been required to modify the child process to added the /clr switch so that it will work as C++/CLI. It now seems that when I attach to the child process, when I try to debug through my code, I am only able to see the values of some C++ variables and some C# variables.
I have read that Visual Studio 2012 update 2 had broken C++/CLI debugging but given that I am using Visual Studio 2012 update 4, can anyone tell me what must be done or what settings must be applied, so that I may debug into a child C++/CLI process and be able to see the values of variables please?
Thanks,
Patrick