If you can still find the Olympus C5500 'Sport Zoom', it might be a good substitute for the C4000. I have no experience with this camera, but I've seen very favorable comments from those who have used it. It appears to be similar in size and features to the C4000. It has more zoom range, but the lens is more than a full stop slower at the long end.
How have you used the C4000? Were its manual control options important to you, or did you stay in fully automatic mode? Was there anything about it you that you especially liked or disliked? Maybe if you tell more about your own photographic style, you can get some suggestions.