What tests have you done to check out the camera & CF cards?
Would strongly suggest either checking the CF cards in another camera or borrow a known working CF card from someone and try it in your own camera. You may find your local camera store may help you out there as they would win a potential customer either way, a new camera or a new CF card.
Remember that CF cards DO have a limited life and if your photography is important to you then they should always be replaced at first signs of problems.
Certainly seems strange that the camera would semi-fail in such a way, normally this type of electronics would either work or not work, rather than half function.