ok i have seen some other members having troubles with the cube not being able to have the top and bottom caps and you can do it and it is actually really easy too.
you will have to enable the desktop cube to start with and enable the rotation in compiz settings
now to set the top and bottom images you need to double click on the CUBE REFLECTION AND DEFORMATION in compiz settings and from there you can set the top and bottom images and you can also make your cube into a sphere :D or a cylinder hope this help you guys out that were having problems with it :)
