Comment 3 for bug 796551

Thank you for taking the time to report this bug and helping to make Ubuntu better.

It looks like another process on your system had a lock on /var/cache/debconf/config.dat.

This is normally a transient situation and should resolve itself. Simply performing the update again should solve this issue.

If it does not fuser -v will return the locking process if any. Kill it and try performing the upgrade again.

Please update this bug report if this resolves your issue.