on Zenwalk, with xfdesktop svn27598 : 

-> Updating an application package (which performs a desktop file update) always crashes xfdesktop.

How to reproduce : 
start xfce
launch xnetpkg
update, remove or uninstall a graphical application


jpgu[~]$ xfdesktop
** (xfdesktop:3655): DEBUG: saturation is 1.0000

Segmentation fault
jpgu[~]$ 
jpgu[~]$