Comment 65 for bug 1335492

Does the bug occur if you reduce the amount of desktop icons?

Other than that, we need to obtain the debug log from xfdesktop when initially started. Assuming that you have a default Xubuntu installation, please follow these instructions:

Copy /etc/xdg/xdg-xubuntu/xfce4/xfconf/xfce-perchannel-xml/xfce4-session.xml to ~/.config/xfce4/xfconf/xfce-perchannel-xml/ and apply the following change:

--- xfce4-session.xml.orig
+++ xfce4-session.xml
@@ -29,6 +29,7 @@
       <property name="Client3_PerScreen" type="bool" value="false"/>
       <property name="Client4_Command" type="array">
         <value type="string" value="xfdesktop"/>
+ <value type="string" value="--enable-debug"/>
       </property>
       <property name="Client4_PerScreen" type="bool" value="false"/>
     </property>

Now relog and attach the output of the filtered session log file:

$ grep DBG ~/.cache/upstart/startxfce4.log