root@matrix-core:~/deb# aptitude -t lenny-backports install xfce4_4.6.1.1~bpo50+1
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Reading extended state information      
Initializing package states... Done
Reading task descriptions... Done  
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 155 not upgraded.
Need to get 0B of archives. After unpacking 0B will be used.
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Reading extended state information       
Initializing package states... Done
Reading task descriptions... Done  

root@matrix-core:~/deb# aptitude -t lenny-backports install xfce4                
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Reading extended state information      
Initializing package states... Done
Reading task descriptions... Done  
The following packages are BROKEN:
  xfce4 
The following NEW packages will be installed:
  aumix{a} xdg-user-dirs{a} xfce4-settings{a} xinput{a} 
The following packages will be REMOVED:
  xfce4-mcs-plugins{a} 
The following packages will be upgraded:
  xfce4-session xfce4-utils 
2 packages upgraded, 5 newly installed, 1 to remove and 153 not upgraded.
Need to get 1703kB/1782kB of archives. After unpacking 2245kB will be used.
The following packages have unmet dependencies:
  xfce4: Depends: xfdesktop4 (>= 4.6.1) but 4.4.2-7 is installed.
         Depends: thunar (>= 1.0.1) but 0.9.0-10 is installed.
         Depends: thunar-volman (>= 0.3.80) but it is not installable
         Depends: xfce4-mixer (>= 4.6.1) but 4.4.2-3 is installed.
         Depends: xfce4-appfinder (>= 4.6.1) but it is not installable
         Depends: orage (>= 4.6.1) but it is not installable
The following actions will resolve these dependencies:

Keep the following packages at their current version:
xfce4 [Not Installed]
xfce4-mcs-plugins [4.4.2-4 (stable, now)]
xfce4-session [4.4.2-6 (stable, now)]
xfce4-settings [Not Installed]

Score is -9791

Accept this solution? [Y/n/q/?] q