I don't know either but I do know what problems it causes. Pages freezing. Firefox not responding. Firefox using too much memory process.

Afeter going through a few things in FF help I ended up have to do a roll back on my pc cos it messed the graphics up

I have to use Chrome for gaming as FF is a waste of time.

Some info here about updating the graphics display driver.

• http://kb2.adobe.com/cps/409/kb409116.html

For freezing problems try this:

The default of the pref network.http.max-connections has been increased from 30 to 256 in Firefox 6+ versions.

You can try to decrease the value of the pref network.http.max-connections from 255 to a more modest setting like 30 as used in Firefox 3 versions.

• https://support.mozilla.com/kb/Firefox+never+finishes+loading+certain+websites