Thunar is daemonized, HAL and d-bus up and running. Scenario: Thunar is not open, if cut/copy files/directories objects from the desktop, then open Thunar, cannot paste (grayed out) into Thunar. But if an instance of Thunar is open and cut/copy is performed from the desktop, able to paste into the open instance of Thunar. This occurs whether I have Parcellite daemonized in the background, or not (though it should not matter either way). No problems with copy/cut & paste actions within Thunar itself. Also, unable to copy/cut paste files/directories between an open instance of Thunar and the desktop.
Clarification on the last sentence of the previous comment. It should read: Also, unable to copy/cut paste files/directories from an open instance of Thunar to the desktop.
Paste isn't implemented on the desktop (see bug #3804). Not sure about the problem of being unable to paste into thunar side, sounds like an issue with thunar. (What is "Parcellite"?)
Confirming this both for Xubuntu Intrepid(Xfce 4.4.2, Thunar 0.9). There is an entry for the "copy from desktop and try to paste to a then opened thunar"-bug, too (see bug #4301). Trying with nautilus on this Xubuntu-desktop and both works. And trying with xfe the paste-to-desktop-bug is present only.
Fwiw, it's still reproducible in 1.1.4 with the GIO xfdesktop
*** This bug has been marked as a duplicate of bug 7024 ***