I dont know why CTRL+Shift+C would not work, only thing I can think of is theres something wrong with your disk...I play the sims 2 daily and I dont have any problems using my cheat bar and I have uninstalled and reinstalled quite a few times due to corrupted user made objects....have you tried going to some official sim forums for further help? you can check out
http://gammasims.forumhoster.com they have a good sims2 forum section and someone is always willing to help the best they can there...Sorry if I am not suppose to post website addys here, I am new here
Hope this helps you out a bit