Checkboxes aren't redrawn when toggling in windowsvista style after the window has been minimized, maximized.
How to reproduce:
1) Create minimal MainWindow with one central widget and in it a checkbox
2) Launch it, maximize it
3) click checkbox , click again
-> Checkbox goes from checked to unchecked to checked
4) Now minimize the application via the windows handle, maximize it again
5) Checkbox isn't redrawn when clicked
This seems to be related to the transitions that are applied if configured by windows theme (default is true).