2.7 image upload issue

HI

I am trying to add images to my new site – specifically on this post http://www.kylieshop.co.uk/kylie-support-breast-cancer-with-her-filofax-design/

Usually when I have tried to add media in other versions i get this the add media form as a pop up. However, rather than opening in a new window, the add media is opening in the same window/tab as the page i am trying to edit and consequently i am not able to place the uploaded image into the post.

Anybody know why?

Thanks
Stephen.