No problems with Firefox 23.0.1 in connecting to any of the sites.
Well the only issue I had was the huff has a geolocation and it threw up an error page as it tried to redirect to the .co.uk site and that required user input to allow it to go to the relocated page.
Since others can access the site/s without problem, it tends to indicate that there is something in the mix, some sort of conflict. Like any conflict remove one part of a conflict and there is no conflict, but that doesn't identify the true culprit.
What version of firefox are you using ?
What other security based software do you have installed (firewall, anti-spyware, etc.) and do you have any security based firefox add-ons ?