context menu works, but not with horizon view. why?

I generate from a existing notepad++.msi with additional registry entries a new notepad++2.msi. When i run/install the new notepad++2.msi on a PC manually, then comes the context menu item "Edit in Notepad++". If i assign the same notepad++2.msi with Horizon View, then the application is installed as normal but the context menu entry is not there!

Waht makes Horizon View different as a normal installation?

i used this tutorial:

http://blogs.vmware.com/thinapp/2011/04/adding-shell-extensions-to-thinapp-packages.html