Okay, my problem coincidentally started a couple of days ago. Whenever I go to support.mozilla.com I get redirected to a page written in French that differs with a daytime and nighttime version (Google translate):
Sorry but the site you are trying to kikoololiser was deliberately blocked by an unscrupulous administrator.Also, the address bar and the tab label are enclosed by a red dotted line.
Sorry, the kikoololisateur is currently closed. Open: 10:00 a.m. to 10:00 p.m. (Europe) each day
The problem is localized to my laptop computer - I've checked other computers on my home network and they can navigate to support.mozilla.com; one using Firefox and another using IE.
In the last few days, I was fixing a friend's computer with your help (http://www.bleepingcomputer.com/virus-removal/remove-personal-security). I was using my USB to transfer tools to that computer, but I didn't put anything from that computer onto the USB stick.
I was also exploring add-ons around the same time, and trying to get HP Smart Web Printing to work by changing IEtab extensions. (Firefox troubleshooting report attached)
I ran Malwarebytes Anti-Malware, which found 2 or 3 problems it fixed (log attached) and AVGfree (report attached)
MS Windows XP Home 32-bit SP3, Firefox 3.6.6, full info from Speccy http://speccy.piriform.com/results/jYSoJV904o9jePdXHo2b7O5
Thank you very much!