I'm suffering exactly the same problem with NVIDIA graphics on Natty. Googling:-
NVIDIA Konsole crash
it would appear this problem has been around for some time on other KDE distros - with no real solution in sight other than a very crude and tricky xserver downgrade.
This is pretty serious because if effectively renders Kubuntu useless for NVIDIA users.
I'm suffering exactly the same problem with NVIDIA graphics on Natty. Googling:-
NVIDIA Konsole crash
it would appear this problem has been around for some time on other KDE distros - with no real solution in sight other than a very crude and tricky xserver downgrade.
This is pretty serious because if effectively renders Kubuntu useless for NVIDIA users.
Best wishes, G