Since upgrading to natty (i have compiled xfce myself from git), when I switch the Task with alt-tab, there are TWO windows show the icons of open applications. I'm not sure, if it is related to xfdesktop. In maverick (xfce 4.6.2 I think), it was still ok. I tried again. I saw, that this is only, if I have a secondemonitor and change the resolution of it with xrandr. If only have one monitor, it is ok.
Created attachment 3281 double window list window
*** Bug 6985 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 6902 ***