Hi, I have ff 3.6.12 and was having same issue.I added ajax.googleapis.com to my adblock filters and now pages load instantly. Don't know if this will help you but it did me, good luck.

Caution: Some web sites may not work..!! with this block..

So..?..

ask yourself if your privacy is more important...??
Than the file or information contained in this insidious web site...?
any web site that uses this abusive, invasive and very persistent google cookie does not care about your browsing privacy...... 

Find::: Windows: C:\Windows\System32\drivers\etc

Open host file w/notepad..

Mine is ...Local Host: .. 127.0.0.1 localhost

Make a Back-up Copy First and save with .old ext 

Add these two lines...

1. [Misc A - Z]

127.0.0.1 ajax.googleapis.com

127.0.0.1 www.ajax.googleapis.com

Note::: you can insert ( Web Site) in the same Alphabetical order to maintain continuity of Local host web sites file (Host)..

Exit&Save

Google has become Micro$oft [Mini-Me]..

To prevent other Google abuses...

Newer Version of Firefox..

user might want to try 

Add-ons:

GoogleEnhancer / 1.90 GoogleSharing / 0.22.1

muggle2 you are wrong, ajax.googleapis.com is a CDN repository for the popular jquery javescript functionality plus others that modern websites utilise.

If you block this then you will stop the website functioning as it was designed to work.

Regards, Renners