On Windows when clicking the popup it seems that it is made the active window which causes a FocusOutEvent with the proper reason. So, on Windows, if the focus is lost due to a application window activation don't hide the completer.

Also on all version if the focus out reason is window activation don't trigger the category creation code this enables the user to switch windows while typing a category name.

This bug is yet another reason to port the account combobox to the QCombobox-QCompleter mechanism.