I have my Windows 8 Desktop taskbar located at the top of the screen. When I open Mockups 3, it puts it title behind the taskbar where I cannot access it. I have to edit the properties of the taskbar to auto-hide, move the Mockups 3 window and then go back to turn off auto-hide.
Thank you for your report. I can confirm the issue. I handed it on to our developer team.
The application remembers the window size, position and if the window was maximized for saved projects. If you start the application by opening a file then you should not have the issue.