cannot launch winswitch_client on arch linux

[cyberic]

I use these versions:
[eric@pc ~]$ pacman -Q winswitch
winswitch 0.12.16-1
[eric@pc ~]$ pacman -Q xpra-winswitch
xpra-winswitch 0.6.0-1

And here are the errors...
I can't really distinguish between 'serious' errors , and 'non-important' errors

I can do some more tests, just tell me...

[eric@pc ~]$ winswitch_client
[DD] 2012/21/09 01:33:01 main_loop.loop_init(False)
[II] 2012/21/09 01:33:01 main_loop.loop_init(False) twisted version 12.1.0
[II] 2012/21/09 01:33:01 globals os.uname=('Linux', 'pc', '3.5.3-1-ARCH', '#1 SMP PREEMPT Sun Aug 26 09:14:51 CEST 2012', 'x86_64')
[II] 2012/21/09 01:33:01 globals python package info: version=0.12.16
[II] 2012/21/09 01:33:01 globals version=0.12.16 (svn revision unknown - unknown local modifications), built on pc by eric, 2012-09-21, release_build=True
[II] 2012/21/09 01:33:01 globals uid=1000, username=eric, name=eric, hostname=pc, locale=en_US, argv=usr/bin/winswitch_client
[II] 2012/21/09 01:33:01 globals Python version 2.7.3 (default, Apr 24 2012, 00:00:54) [GCC 4.7.0 20120414 (prerelease)]

(process:20193): WARNING : Trying to register gtype 'GMountMountFlags' as enum when in fact it is of type 'GFlags'

(process:20193): WARNING : Trying to register gtype 'GDriveStartFlags' as enum when in fact it is of type 'GFlags'

(process:20193): WARNING : Trying to register gtype 'GSocketMsgFlags' as enum when in fact it is of type 'GFlags'
[II] 2012/21/09 01:33:01 process_util.<module>() using twisted ProcessProtocol?=winswitch.twisted.HiddenSpawnedProcess?.HiddenSpawnedProcess?
[EE] 2012/21/09 01:33:01 distro_packaging_util.get_distro_helper() failed to load dbus packagekit: org.freedesktop.DBus.Error.ServiceUnknown?: The name org.freedesktop.PackageKit? was not provided by any .service files
Traceback (most recent call last):

File "/usr/bin/winswitch_client", line 5, in <module>

winswitch.client.client_wrapper.main()

File "/usr/lib/python2.7/site-packages/winswitch/client/client_wrapper.py", line 52, in main

from winswitch.client.client import main

File "/usr/lib/python2.7/site-packages/winswitch/client/client.py", line 14, in <module>

from winswitch.client.client_base import ClientBase?

File "/usr/lib/python2.7/site-packages/winswitch/client/client_base.py", line 28, in <module>

from winswitch.objects.server_config import ServerConfig?

File "/usr/lib/python2.7/site-packages/winswitch/objects/server_config.py", line 14, in <module>

from winswitch.objects.server_base import ServerBase?

File "/usr/lib/python2.7/site-packages/winswitch/objects/server_base.py", line 27, in <module>

from winswitch.util.commands_util import SEAMLESSRDP_COMMAND

File "/usr/lib/python2.7/site-packages/winswitch/util/commands_util.py", line 70, in <module>

dh = get_distro_helper()

File "/usr/lib/python2.7/site-packages/winswitch/util/distro_packaging_util.py", line 141, in get_distro_helper

installer(XPRA_TYPE, "xpra")

TypeError?: 'NoneType?' object is not callable