Mozilla links reports that according to Giorgio Maone , the author of NoScript, a popular Firefox addon, a bug in the xorg-server package in the latest released Ubuntu 10.04 is causing Firefox sessions to crash when the NoScript add-on is installed.
“I’m receiving several reports by Ubuntu and Debian users having their desktops crashed as soon as they click the NoScript icon. Yes, your whole session gone, back to your logon page in one move!
Actually this may be triggered by different actions, not necessarily with NoScript installed, or reportedly just by having a long/complex enough interaction with Firefox.
It turns out to be a bug in the xorg-server package, which Ubuntu’s maintainers deemed not worth to get fixed before releasing Lucid Lynx.
Giorgio also reports that the bug is also causing Firefox sessions to crash even in NoScript add-on is not installed in the Firefox browser.
Mozillalinks also points out that , a patch to fix the bug is already available but it isn’t available as automatic update. To get the update Ubuntu users has to run below command
sudo add-apt-repository ppa:bryceharrington/purple && apt-get update && apt-get upgrade