[KDE4] Conversation with su failed

I’ve changed from previous 2.6.29 kernel to 2.6.31-rc4 (testing some patches).
Everything works, except kdesu throws:
“Conversation with su failed” everytime I would like to launch e.g. yast as root.

I haven’t touched anything else on my system - /etc/sudoers seems fine.
Is there something in the kernel doing this? What could it be?

Try this, worked for me.

Open a shell, run sudo su - to become root (or however you need to do it).

Once at a root shell, run visudo, save the file as it is, and exit vi.

For some reason this fixed the problem for me.

See Bugs:Most Annoying Bugs 11.2 dev - openSUSE for a work-around.

I’ve upgraded to .31-rc5 and now works again. Probably some kernel problem.