Viewing a video (YouTube, etc.) disables the mouse scroll wheel - switch to Opera and scroll on a page, return to FF and wheel is reenabled.
After viewing a video (usually YouTube, but not exclusively; either directly, or embedded in a web page), the mouse scroll wheel will become disabled. If I then switch over to Opera and use the scroll wheel on any open page, the scroll wheel will be re-enabled upon return to FireFox.
After viewing a video (usually YouTube, but not exclusively; either directly, or embedded in a web page), the mouse scroll wheel will become disabled. If I then switch over to Opera and use the scroll wheel on any open page, the scroll wheel will be re-enabled upon return to FireFox.