[PROBLEM] Package upgrade error

[Eruurk]

Hi,
I am using XBIAN 20150112-4 on my Raspberry Pi model B.
I tried to upgrade my packages as requested by XBIAN-update tool (from XBMC or via SSH).
I have these two packages to upgrade :
- xbian-package-config-xbmc
- xbian-package-upstart-xbmc-bridge

When I try to upgrade these packages I encounter an error :

Terminal

xbian@xbian ~ $ sudo apt-get install xbian-package-config-xbmc
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
xbian-package-config-xbmc : Depends: xbian-update (>= 1.0.2-7c) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

So I tried to upgrade xbian-update manually, without success

Terminal

xbian@xbian ~ $ sudo apt-get install xbian-update
[sudo] password for xbian:
Reading package lists... Done
Building dependency tree
Reading state information... Done
xbian-update is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.

Here my repo list

Terminal

xbian@xbian ~ $ cat /etc/apt/sources.list
deb http://mirrordirector.raspbian.org/raspbian/ wheezy main non-free

I search on the Internet a solution to this issue but I did not found anything usefull.

Could you please help me to resolve this problem?
Thank you very much for your support.

Regards,
Eruurk