Yes I noted that and thought I'd give it a go. It seems to work, I'm sure it's working better now than it was but I don't know if that's just me as I've no way of testing - hasn't done any harm anyroad.
Many of the tweaks that are discovered and given often end up being added to the next updated version, if the developers feel that it would improve the product without creating a poorer product which may in the long term cause a fault or weakness in the use and security to develope. The actual Firefox / Thunderbird / Mozila foundation is open source and made by a group of dedicated people who have built this product range out with funding from commercial sources and do it for the pleasure of developing their own thing and continually making it better, in the long run they have succeeded in creating a stable and very good product.
If nglayout.initialpaint.delay doesnt exist, Right click, new integer.
Close mozilla and start it again. Now Mozilla Burns sites like wild.
WARNING: These settings make you download sites considerably faster, BUT put a great overload on the sites you go to. This really means nothing other then the fact that anyone else browsing will just go slower and you will absorb their speed.