kwin effect shortcuts-how to?

Hi everyone. I wonder how to set shortcuts for effects in kwin in kde 4.2? When I go to Configure Desktop->Desktop->Desktop Effects->All Efects and select Desktop Cube for instance, when trying to set the shortcut key lets say letter “u” at the bottom window, it says “The shortcut ‘U’ conflicts with the following key combinations:” It conflicts with nothing?! It doesn’t help if I select any other letter or key combination, what am I missing here :frowning: ,thanks for your help.

Did you try a key combination such as Alt+F9 etc.? Simple keys (like just “u” etc.) should not be used.

thanks, yes I did, but for some strange reason it won’t allow any shortcut to be selected, it says it conflicts with empty one. Now I managed to setup compiz correctly, so I don’t need kwin at the moment, but would like to know the solution anyway, if someone figures it out.