1. Enabling secondary monitor is slow. 2. Startup and login becomes very slow when secondary monitor is enabled.

[Regin]

1. Enabling secondary monitor is slow
- The system basically hangs, the mouse moves slowly and I'm not able to open other application until the configuration is complete.

2. Start up and login becomes very slow when secondary monitor is enabled
After I've passed the login window it takes ages before I reach the desktop and I am able to start working.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: systemsettings 4:5.2.2-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-26.28-generic 3.19.8-ckt4
Uname: Linux 3.19.0-26-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.17.2-0ubuntu1.3
Architecture: amd64
CurrentDesktop: KDE
Date: Mon Aug 24 16:05:31 2015
ExecutablePath: /usr/bin/systemsettings5
InstallationDate: Installed on 2014-11-03 (294 days ago)
InstallationMedia: Kubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: systemsettings
UpgradeStatus: No upgrade log present (probably fresh install)
XsessionErrors: (process:2647): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed