Ubuntu 14.10 shut down slow after sleep

[Macro Zhu]

I upgraded from 14.04 to 14.10 recently. My laptop does not shut down properly anymore. It used to take only 5 sec to shutdown in 14.04. But now it needs ca. 5 min to shut down after sleep. If it never slept, then shut down process is normal. The message on the shut down screen has something to do with ModemManager:

ModemManager: ModemManager is shut down

ModemManager: Could not acquire the 'org.freedesktop.ModemManager1' service name

it stays like that for ca. 5 min before it suddenly shuts down.

I added stop on runlevel [06] to the network-manager.conf file. It did not help.
I used shutdown -h now. It did not help.

modemmanager:
  Installed: 1.2.0-1
  Candidate: 1.2.0-1
  Version table:
 *** 1.2.0-1 0
        500 http://archive.ubuntu.com/ubuntu/ utopic/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: modemmanager 1.2.0-1
ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4
Uname: Linux 3.16.0-24-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
CurrentDesktop: KDE
Date: Tue Nov 18 15:10:26 2014
InstallationDate: Installed on 2012-03-22 (970 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
SourcePackage: modemmanager
UpgradeStatus: Upgraded to utopic on 2014-10-24 (25 days ago)
mtime.conffile..etc.init.modemmanager.conf: 2014-11-18T10:37:43.218538

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Macro Zhu (zhu-macro)]

I have the shutdown time improved by editing both /etc/init/modemmanager.conf and /etc/init/network-manager.conf via adding a line to them:

kill timeout 1

The original post on that idea is from:

http://www.hecticgeek.com/2012/10/speed-up-ubuntu-shutdown-process/

[Macro Zhu (zhu-macro)]

The hardware is a Lenovo x121e.

Ditch ModemManager "solves" the problem. But I would say it is not a proper solution.