I guess it is impossible to tell what is happening on your machine, but have you considered a local problem, like a malware infection of your system? Things you might try if you have just a little computer knowledge - or some friend who has:

try to install an alternative browser and see if the problem persists:

www.opera.com
www.firefox.com

Both browsers are "one click" downloads and a second click to install. If these browsers run fine, make sure to do a full malware check of your computer with a good up to date Antivirus product. Kaspersky would be a good choice and runs for free for at least 30 days.

If the problem persists, go to www.sun.com and download the current Java package. Do a re-install.

If the problem still persists, try the following:

www.knoppix.org

At that site, you can download a "Live Linux" DVD image, which needs to be burned to a DVD, of course. Your computer must be able to boot from a DVD. Boot Knoppix, which will take you all the way to a running, graphical desktop with many applications, including Firefox. If this brings back your flyertalk completely, your Windows installation is infected by something. Knoppix includes tools to eradicate Windows malware, but you should only try this with at least mid-level computer knowledge.

The reason I recommend the Live Session DVD/CD approach is that this is the only way to make sure that you boot a clean, infection-free system.