Which would explain why the problem returns as some other process or cron job restarts the process that handles those particular mappings. The fact that this works seems like a side effect, rather than a cure. The disk utilities/repair permissions fix is puzzling, without examining your machine I'd say one or both of those utilities are interrupting some key mappings (either by shutting down/suspending a process or performing some override in the windowing subsystem). *EDIT* - to test the Spaces theory, change the number of spaces you have enabled from 4 to 2 and see if that reduces your problem allowing you to set grouping on numbers 3 and 4. Unfortunately, I don't see a way to re-map C&C3. I've noticed that C&C3 does a pretty good job of overriding the application UI layer, so this is most likely a system process conflicting with the game. If this works have a hard look at your keyboard mappings (check Spaces first) to move the conflicting setup(s). If you have the ability to try using a newer Mac keyboard (w/number pad) and a 3 button USB mouse (not the mighty mouse) you may find your problems go away. I do have Expose & Spaces enabled and that doesn't pose any problems. My best guess at this point is keyboard mappings, I'm using the 'newest' iMac keyboard, which is mapped differently from previous versions.

Command and conquer mac alternate