Odd display issue

[Zosimos]

The last few versions of Firefox have shown a strange behavior. When displaying a page it will stop redrawing with only some of the page on the screen, leaving large blocks (square/rectangular) spaces just black. Scrolling the page up or down a bit forces it to complete, so it's not some sort of major crash. It's just not finishing the render. This is a Windows 7 system with a E8600 Intel CPU (yes, pretty old) and an nVidia GTX-650 video card (yes, also pretty old). I've not seen any other browser do this, and I have several on the machine. Anyone else seen this?

[kerft]

Webrender has been recently enabled on more computers. Disable webrender and restart the browser to see if that is a fix. Go to url address about:config and find gfx.webrender.all and set to false. If it was already false, this is not the problem and you could experiment with disabling hardware acceleration (in firefox options).

[Zosimos]

There are three settings that match this when I put it into the about:config bar.
app.normandy.startupRolloutPrefs.gfx.webrender.all.qualified
gfx.webrender.all
gfx.webrender.all.qualified

Only the shorter one, the one you mention, is false. The other two are true. Weirdly. the app.normandy one is in bold, meaning it has been changed from its default. When I set it to false and restart, it gets set to true again... ??? What is this app for? I don't recall installing it in Firefox.