Changing mouse sensitivity using buttons on mouse or on program while game is open results in crash of game to desktop, same sort of issue as volume change.
mice tested: Mad Catz R.A.T. 9 & Razer Lachesis 5600
EDIT: only happens when minecraft is topmost (currently selected program).eg; I can switch to chrome and change volume while minecraft is in the background & it wont crash.
Your game version is already ancient by now, update it.