When enabling Reverse Scroll Direction under the Mouse settings of the Input Devices, only vertical scrolling is affected. Horizontal scrolling does not get reversed. Reproducible: Always Steps to Reproduce: 1. Go to System Settings - Input Devices - Mouse 2. Enable Reverse scroll direction and apply 3. Scroll a large document, like a wide webpage in a small browser window, with a horizontal-axis capable mouse (or a touchpad) Actual Results: Horizontal scrolling is unaffected Expected Results: Horizontal scrolling is reversed, just like "natural scrolling" does under OS X or the net effect of dragging contents in a touch-enabled device.
*** This bug has been marked as a duplicate of bug 296143 ***