Option is not saved: "Allow SourceTree to modify your global Git and Mercurial config files"

The following option setting is not persistent:

Options -> General -> Allow SourceTree to modify your global Git and Mercurial config files

After unchecking this option, the checkbox remains unchecked for as long as the app is running. When the application is exited and restarted, however, the option is always reset to its checked state.