I am experiencing persistent rendering errors with Mozilla Firefox 50.1.0 that make this browser unusable on many sites, particularly bulletin-boards. The same error occurs when Firefox is opened by a 'New User' on this system. The images below show this page rendered by Firefox and Konqueror (4.14.27, Web-kit) on this system and explain the problem better than I can in words.

snap-firefox

snap-konq

I have been unable to find the cause nor a remedy and would be grateful for technical advice.

OS: Linux 3.12.67-64-desktop x86_64
System: openSUSE 13.1 (x86_64) KDE: 4.14.27
Display: nvidia GeForce GTX 560/PCIe/SSE2