Davide,
Could you clarify whether you are trying to use key bindings specified in the CodeMix user/workspace settings or those specified in the Eclipse key bindings? If you go to the key bindings in the eclipse preferences and search for “case” you will see bindings for “Editing with CodeMix” (in fact, if you search for “CodeMix”, you’ll see all bindings we’ve added for CodeMix). Did you try those bindings?
If you still see the problem, could you please let us know the editor in which you are trying to use the key binding?