Make sure that you aren't blocking JavaScript.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do not click the Reset button on the Safe mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

See also:

• http://kb.mozillazine.org/Websites_look_wrong
• https://support.mozilla.org/kb/Websites+look+wrong

Thank you cor-el! In Safe Mode I don't have the problems. Now to figure out which Add-On is causing the problem.

cor-el,

It was PrivacyFix and I've removed it. I had heard about PrivacyFix on TV the same day as I updated Firefox.

Many, many thanks!!

I have problem wearing Themes and add-ons in my mozila 16.0.1 I add theme or some personalization and after closing mozila all the things i have added vanish.I tried cleaning cache but no result. And what is this PrivacyFix? - one of the times when i reinstalled mozila a windows poped up saying that some program wants to make changes to the personal appierence of my browser. PLZ help! :)

PrivacyFix is an Add-on that tells you when websites try to grab some of your personal information.

As for your problem with Themes, I think you should post it separately under a new title so it can be seen.

ok ty