Same discussion in this thread.

Same problem here. Mouse gestures and keyboard within the browser-window do not work after a random amount of time. I only use mouse gestures to close tabs.

My active addons are: Dark theme for all Websites - Download Chrome extension - Evernote web clipper - Ghostery - Java script switcher - Scroller - Session buddy - Shortcuts for Google products - Violent monkey - Youtube to mp3

Violent Monkey scripts: Three scripts which prevent hijacking mouse buttons and keyboard

Opera 32.0.1948.25 stable, Windows 7 64-bit, Aero design active