Text smudged/blurred - hardware acceleration on, page very slow/unresponsive when off

Question

Other users have reported the same problem but the proposed solution does not work for me.
The text is blurred/smudged - only on Facebook, probably because the page is quite big. If I turn off hardware acceleration, the text is no longer blurry but the page becomes almost unresponsive - the smooth scroll is lost, actually, there's no scrolling at all - the page moves half-screen at a time (per scroll), or sometimes doesn't scroll at all.
My hardware isn't the newest thing out there but isn't that bad either, I'd imagine: AMD Phenom II X4 945 (4 x 3 GHz) and Sapphire Radeon HD 4670 (1 GB). So, if Firefox can't use the graphics adapter, isn't the processor powerful enough for it to properly render a page like FB?

Answer 1

I created a new boolean called "layout.paint_rects_separately" and set it to "true".
I haven't done much testing yet -- just opened FB a couple of times -- but I don't notice any smudging. Let's say problem solved!
I will write again here if it re-occurs.
Thank you!