I have my class ability set to scroll wheel down, and I noticed that when I scroll downwards in the Nav Mode menu to look at my bounties, quests, etc, the menu closes because of the class ability binding. The class ability does not trigger, and the menu does scroll down, but I do have to reopen the menu again to read it. I have my grenade binded to the scroll wheel button(click down), but I have not tested what happens when I press it.