Seems to be a problem with AppArmor. It's a program that's supposed to enhance security, but sometimes it causes obscure errors. (Not that I know much about what it does... but I've seen tutorials written by competent people where they suggest that you turn off AppArmor in Ubuntu Hardy.)
Try running the following commands:
Code:
/etc/init.d/apparmor stop
update-rc.d -f apparmor remove
The first line stops AppArmor and the second line prevents it from being started the next time you reboot.
Or maybe you can just apt-get remove apparmor. And reboot. (You don't really need to reboot because this isn't Windows, but just to make sure that the error doesn't appear when rebooting...)
Hope this helps,