Steps to reproduce: run xfrun4 or xfce4-appfinder

What I expect to happen: the programs should launch almost immediately
What happens instead: it takes several seconds for them to launch.

When I run one of the commands from inside a terminal I get the following error message:

(xfrun4:2882): xfce4-appfinder-CRITICAL **: Failed to open window: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Ubuntu version + package version:

$ lsb_release -d
Description: Ubuntu quantal (development branch)

$ apt-cache policy xfce4-appfinder
xfce4-appfinder:
  Installed: 4.10.0-1
  Candidate: 4.10.0-1
  Version table:
 *** 4.10.0-1 0
        500 http://de.archive.ubuntu.com/ubuntu/ quantal/universe amd64 Packages
        100 /var/lib/dpkg/status