Desktop effects in XDMCP session

[Alvin]

I'm under the impression that XDMCP isn't very popular nowadays.

Anyway, I do have a question: how do you make desktop effects work within an 
XDMCP session. I know it should work, but what are the conditions?

The X client runs (JeOS) Kubuntu, while the X server just has xserver-xorg and 
hal. The X server has a recent nVidia card and the nvidia-glx driver works.

The xorg.conf is no more than:
	Section "Device"
	    Identifier     "Default Device"
	    Driver         "nvidia"
	    VendorName     "NVIDIA Corporation"
	    BoardName      "GeForce 9400 GT"
	EndSection
	
	Section "Module"
	        Load    "glx"
	EndSection