VS2013 debugging Vspackage

Hi,

I am having a VSPackage for my source control. I am trying the project in VS2013 update 3 by launching an experimental instance. But the package is not loading in the experimental instance. But the same project works fine in VS2012, it loads properly in VS2012 experimental instance. Not sure what I am missing. I have the following settings in the project properties. 

External Program: C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe

Command Line Arguments : /rootsuffix Exp13

Thanks,

Rajiv.