this is very weird kde3 was working fine and then in the middle of a session everything seemed to freeze and after shutting down the computer and starting kde3 again everything is still the same! I've found out that I can use applications, but no buttons or menus are functional. I have to use key combinations to do anything. After some fooling around, I found out that I can enable menus every once in a while by right clicking on the background?????? but that doesn't last very long and I have to try to re-enable them by clicking on the background; for instance after writing this message in a text box, all the buttons and menus are disabled again.

Here is what I get when I start kde with 'startx' :

DCOPServer up and running.
Mutex destroy failure: Device or resource busy
mcop warning: user defined signal handler found for SIG_PIPE, overriding
QWidget::setMinimumSize: The smallest allowed size is (0,0)
QWidget::setMaximumSize: (unnamed/DigitalClock) Negative sizes (2,-4) are not
possible
QWidget::setMinimumSize: The smallest allowed size is (0,0)
QWidget::setMaximumSize: (unnamed/QLabel) Negative sizes (49,-4) are not
possible
QWidget::setMinimumSize: The smallest allowed size is (0,0)
QWidget::setMaximumSize: (unnamed/DigitalClock) Negative sizes (2,-4) are not
possible
QWidget::setMinimumSize: The smallest allowed size is (0,0)
QWidget::setMaximumSize: (unnamed/QLabel) Negative sizes (49,-4) are not
possible
QObject::connect: No such slot KWrited:: block_in(const char*,int)

you can try deleting some of the config files in your home folder.

like .kde .kderc

well it took a lot of deleting, but I finally deleted something that set it all back to normal. thanks

I found this thread and ive been hving a similar problem. I primarily occurs when running x as a user. kde applications such as the greedy knoquerot and the cups printer gui are effected particulary when they are opened from a root console. I actuslly did a fresh install a few days ago and im still recieving this error. I wonder if this is a bug or if there are dependency permission problems. I see plenty of posts suggesting checking /tmp and /~ permissions or removing .kdestuff but a have yes to see an explination or a working solution.
Im hoping comeone could drop some knowledge.
issued in su console but in a user x login.
bsd# konqueror
DCOPServer up and running.
mcop warning: user defined signal handler found for SIG_PIPE, overriding
/tmp/mcop-jacob is not owned by user
bsd# kdeinit: Fatal IO error: client killed
kdeinit: sending SIGHUP to children.
Mutex destroy failure: Device busy
kdeinit: sending SIGTERM to children.
kdeinit: Exit.

thanks