Konsole: Permission of TTY cannot be changed (after update)

[roelio_]

Yesterday I recompiled my kernel in order to emerge the new nvidia drivers. After that i did an `emerge --update --deep world'. Everything seems to work fine, but today when I tried to execute 'su' in a Konsole (I use KDE 3.1), I've got for the very first time the error

su: Permission denied
Sorry.

First I thought that the root password was mistyped, but after rechecking it, it wasn't. I tried to `login root' and this too didn't succeed. I've got the error:

FATAL: cannot change permissions of TTY: Operation not permitted

Does anyone has a clue about how I can fix this?

TIA,
Roel

[roelio_]

okay, it seems the problem is already known and even a faq:
https://forums.gentoo.org/viewtopic.php?t=23378

sorry for bothering