Cannot open Properties Window for custom project in Visual Studio 2012 solution

Hi there,

We've an integration to Visual Studio from our project using a VSPackage developed in VS 2005 which creates a custom project(extension .cw) with its own editor using our own templates. We were able to open project properties window(right click on project in solution explorer and select "Properties" context menu item) for our custom project in VS IDE in VS 2005 and VS 2010, but not in VS 2012. Selecting "Properties" context menu item in VS 2012 is doing nothing, not opening the properties window nor throwing any exception. Could someone suggest what the issue could be? Thanks for the help in advance.

Regards,

Rama