Does the issue still occur if you start Firefox in Safe Mode? http://support.mozilla.com/en-US/kb/Safe+Mode

How about with a new, empty profile? http://support.mozilla.com/en-US/kb/Basic+Troubleshooting#Make_a_new_profile

Well, I didn't have to do a thing. The pages started to display correctly so I guess something changed from the several days I had this problem with the new Firefox version. Everything displays as it should now.

I suspect that I wasn't the only one with the problem and that's how it got corrected. Now if you'd do the same for Thunderbird I really be happy. I have abandoned Thunderbird as it simply won't send emails. It says it can't receive them either but it does. I've gone back to Outlook which I don't like.

If it happens again then clear the cache and the cookies from sites that cause problems.

• "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites causing problems: Tools > Options > Privacy > Cookies: "Show Cookies"