As a NewsBlur user, please reduce the sensitivity of or disable the horizontal mouse scroll actions to switch between original/feed/story modes, to reduce unintentional mode switching on input devices such as trackpoints that do not segment between pure vertical and horizontal scrolling.
Horizontal mouse scrolling? That’s a new one. I don’t believe I’ve seen this before. What’s your browser/OS?
Several mice allow the click wheel to be pushed from side to side to scroll horizontally; Apple’s Magic Mouse scroll nub scrolls in any direction, and touchpads, particularly multitouch-capable pads, scroll in any direction. Lenovo/IBM-style pointers scroll by pressing the center mouse button, then pressing the pointer in the appropriate direction. I believe the default action of the middle mouse button on Win7 is to activate a mode that translates relative mouse movement to scrolling direction and speed.
I can’t tell if NewsBlur is handling horizontal scrolling as left or right arrow key presses, or if the driver is doing this. I don’t have a mouse that supports hardware horizontal scrolling at the moment but will when I get home. (The middle-mouse-button scrolling on Firefox isn’t triggering it.)
However, on that laptop I haven’t had this problem on other sites that interpret left or right arrow key presses, such as Gawker sites.
Confirmed that this happens on the ThinkPad when scrolling with the pointer, and I couldn’t reproduce on other sites that use keyboard navigation, so I don’t think the driver is emulating the arrow keys for horizontal scrolling.