So, I had this problem on Windows 7 as well, now I have it on Windows 8.1 - and I thought that I may as well report it…
Sometimes (often) when I want to close Cubase, the “X”-Button of the main application windows doesn’t really work and I have to click it multiple times before Cubase quits (not that I like to quit Cubase that much… ).
Am I the only one with this issue or is that something more commonplace?