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

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

Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information.
Note: This will cause you to lose any Extensions and some Preferences.

• Open websites will not be saved in Firefox versions lower than 25.

To Reset Firefox do the following:

For Firefox versions previous to 29.0:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

For Firefox 29.0 and above:

1. Click the menu button , click help and select Troubleshooting Information.Now, a new tab containing your troubleshooting information should open.
2. At the top right corner of the page, you should see a button that says "Reset Firefox". Click on it.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

As I said previously, I tried Firefox 31 with a new profile so I think it is the same thing that resetting it isn't it ?

I have already tried in safe mode with no change but I will give it a new try

In fact, the shaking of the screen seems appears when the personnal bar is displayed and not when it is not displayed.

this happened to me a few minuites ago, i thought it was just general lagg of my computer but then i checked my internet connection, tried loading google and it was so slow. rebooted my computer and still nothing. But then, i reload internet and everything is fine... long story short i think its down to internet connectivity.

it seems to be related to the bookmarks firefox toolbar (what I called personnal bar two post earlier)

The bug still continues even with the bookmarks firefox toolbar disabled.

What content is there on the Bookmarks Toolbar?

Is there anything other than "Bookmarks Toolbar items" if you check the in Customize mode?

• "3-bar" Firefox menu button > Customize
• View > Toolbars > Customize

Are there any other toolbars present in Firefox?

You can check for problems caused by a corrupted localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

- What content is there on the Bookmarks Toolbar? there is all the bookmarks, 40-50 bookmarks more or less.

- Is there anything other than "Bookmarks Toolbar items" if you check the in Customize mode? ! yes there is the torrent finder toolbar and a button to show my torrent's status with my torrent client, but there are a line below the bookmarks toolbat items

I precise that i changed my distro today with a fresh install and put the 64 bits of Ubuntu instead of the 32 bits but I kept my home and my data separate.