Integrating IDE with Two Versions of Visual Studio

I have Visual Studio 2010 and 2013 installed on my machine for compatibility with other developers I work with. Both are full versions (Ultimate).

I have done the IDE Integration with the 2010 version and it’s working fine, I’m well pleased with it. I’d now like to also integrate it with the 2013 version. When I run the IDE Integration wizard, however, the Visual Studio option is checked and grayed out as is the dropdown list on the next screen. I know from first time around that both versions are in the list.

I’ve spoken to Visual Paradigm support and they say there is no way around this as it is a Windows limitation but I’m not convinced of that. Aware of the ingenuity of the user community, I am wondering if anyone has found a way around it?