You may have discovered this by now, but just in case:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste javas and pause while the list is filtered

(3) If the javascript.enabled preference is bolded and user set to false, double-click it to toggle it back to true.

If you use extensions (Firefox/Tools > Add-ons > Extensions) that can block content (e.g. Adblock Plus, NoScript, Flash Block, Ghostery) then make sure that such extensions aren't blocking content.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Lo and behold it is because of the name used for the javascript function --> scroll(). I have no idea if this always was a reserved word in js or if FF recently got strict about the issue but the bottom line is that everything was fine until the 36.x series of FF.

See https://developer.mozilla.org/en-US/docs/Web/Events/scroll

Possibly the same issue with scrollTo: why did scrolltop stop working in firefox 36?

cor-el thanks for the link but that is all greek to me. I have no idea in hell what it is saying.