Hello lotsmon, You can modify mousewheel.with prefs on the about:config page to disable actions for specific modifiers. *https://wiki.mozilla.org/Gecko:Mouse_Wheel_Scrolling 0 means "Do nothing" 1 means "Scroll contents" 2 means "Go back or forward in the history" 3 means "Zoom in or out the contents" mousewheel.default.action mousewheel.with_alt.action mousewheel.with_control.action mousewheel.with_meta.action mousewheel.with_shift.action You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue. http://kb.mozillazine.org/about:config Thank you