Sounds more like a keyboard problem then a Browser issue. A working Browser will not do what your saying.

WestEnd said

Sounds more like a keyboard problem then a Browser issue. A working Browser will not do what your saying.

Hi WestEnd, if you click on an empty area of a page, not in a form field, the space bar works like Page Down, and Shift+Spacebar works like Page Up. At least that's what I see on Windows 7.

I created a user script which I think prevents this. A user script is a snippet of code that is run in the context of the web page. You can apply userscripts using any of these extensions (you only need one):

• Violentmonkey: https://addons.mozilla.org/firefox/addon/violentmonkey/ (what I used for testing)
• Tampermonkey: https://addons.mozilla.org/firefox/addon/tampermonkey/
• Greasemonkey: https://addons.mozilla.org/firefox/addon/greasemonkey/ (the original, but the WebExtensions version of Firefox 57+ is a work in progress)

The script:

https://greasyfork.org/en/scripts/38545-prevent-spacebar-doing-page-down

jscher2000 said

I created a user script which I think prevents this. A user script is a snippet of code that is run in the context of the web page. You can apply userscripts using any of these extensions (you only need one):

• Violentmonkey: https://addons.mozilla.org/firefox/addon/violentmonkey/ (what I used for testing)
• Tampermonkey: https://addons.mozilla.org/firefox/addon/tampermonkey/
• Greasemonkey: https://addons.mozilla.org/firefox/addon/greasemonkey/ (the original, but the WebExtensions version of Firefox 57+ is a work in progress)

The script: https://greasyfork.org/en/scripts/38545-prevent-spacebar-doing-page-down

Thanks for giving me an idea. I changed it to (key.keyCode === 32) for it to work though.