Dunno if this is relevant but I had a problem like this long ago, like about 2 years back.

I'd fiddled with Firefox's about:config page to allow more connections to whatever website you were visiting on order to get the page to load faster. Except I overdid it and pages would stop loading properly. What was happening was Firefox would try to establish all these connections with the server. One connection for each element (such as an image) because I had it set so high (something like 1024 connections maximum.) Of course the server wouldn;t allow som many connections so the page would never load completely.

Maybe it's relevent. Maybe not. Just so you should know I am rather drunk at the moment...