Comment 3 for bug 976159

Created attachment 70217
the error message

Muon refuses to perform the current update to my system. I am trying to let it perform the April KDE updates from the kubuntu backports archive. When I click "Full Upgrade" then "Apply Changes" the update fails with the following error:
"Another application seems to be using the package system at this time. You must close all other package managers before you will be able to install or remove any packages."

I ran "ps -efl | egrep 'apt|dpkg'" and the only process that shows up is:
4 S root 2393 1 0 80 0 - 20790 poll_s 15:20 ? 00:00:00 /usr/bin/python /usr/share/apt-xapian-index/update-apt-xapian-index-dbus

Killing that process does not help.

I have tried the following, all fail to correct the problem:
1) sudo dpkg --configure -a
2) Logout
3) Reboot
4) All possible combinations of the above.

The only way to get past this is to use terminal:
sudo apt-get update
sudo apt-get upgrade

After that, the problem goes away.