Scroll direction on trackpad vs. mouse

I'm not sure why, but it seems that when you select or deselect 'Natural Scrolling' for either the trackpad or your mouse, it automatically matches that setting on the other so you can't have it be different. Since they are in different areas in System Preferences, you'd think one could choose what they like better, which for me is natural scrolling on the trackpad and standard scrolling on my Logitech mouse. Currently, I use a docking station while at my desk, so that's when I use a mouse, but when I leave, I just use the trackpad, so changing this setting every time is getting a bit old...help!