I'm not entirely sure if this is a flaw with the beta, or with my mouse. Unfortunately, I don't have a spare mouse to interchange and test.
I have a Logitech Mouseware 9.76 Optical Mouse, as far as I can gather from the product papers I still have.
Anyway, I have tested it many times by pressing firmly and squarely on the close button in the research or diplomacy screen and it has failed multiple times.
Has anyone else experienced the same problem, for I am still unsure on whether it is a bug, or just my mouse failing.