Kde 4.3.1 is released with a couple improvements and bug fixes.
Some notable changes from complete changelog :
*KDE 4.3 is now also available in Croatia.
*A crash when editing toolbar setup has been fixed.
*Support for transferring files through SSH using KIO::Fish has been fixed.
*A number of bugs in KWin, KDE's window and compositing manager has been fixed.
*A large number of bugs in KMail, KDE's email client are now gone.
Installing KDE 4.3.1 in Ubuntu Jaunty:
Open your sources.list:
$gksudo gedit /etc/apt/sources.list
and add the following repository at the end of the file. Save the file when you are done:
deb http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu jaunty main
Add GPG keys:
$gpg --keyserver keyserver.ubuntu.com --recv 2836CB0A8AC93F7A
$gpg --export --armor 2836CB0A8AC93F7A | sudo apt-key add -
Now you can update your list and do a dist-upgrade to upgrade to KDE 4.3.1 :
$sudo apt-get update
$sudo apt-get dist-upgrade