I had a hunch that Windows 7 display scaling might be involved, so we did some tests and managed to reproduce the problem. In Control Panel -> Appearance and Personalization -> Display, make sure you're using one of the 3 predefined options - Smaller, Medium or Larger: It's possible to use a custom setting by clicking 'Set custom text size (DPI)', but doing so seems to cause this issue. It works fine (for us, at least) if you stick with Smaller, Medium or Larger. If yo