k on this, and when it asks for a value enter: 0 (Default: 2)
5.
The next preference is “mousewhee... mlines”. Double-click on this, and then enter: 1 (Default: -1)
6.
The last preference is “mousewhe... just double-click it until it changes to “true”. (Default: false)
After you do this, all 3 lines should be... xt, showing that you have changed them from their default values.
To fix it in Opera:
1.
Open up