AFAIK it takes a long wait for a Casio DC to format the camera's internal memory as well as SD cards. But this is the only instance the camera may hang up which I know of.
If the S770 freezes up during other operations, try doing the following:
1. Remove the battery from the camera and let it sit for a while;
2. Make sure the battery is in full working condition, otherwise get a new one and have it fully recharged;
3. Put the fully charged battery back into the camera, perform a hard reset if possible;
4. Turn on the camera, test all functions and see if the problem still persists.
If the above steps don't remedy your problem, then perhaps there's conflict with the internal electronics which needs to be resolved at the repair centre, ie. Jebsen. Have the camera checked up there.
2008-02-03 19:40:34 補充:
It is much safer to bring the defective camera to Jebsen first, rather than to other third-party technician. Otherwise, you will void the original warranty. Third-party technicians are good at repairing out-of-warranty products, and that should be treated as the very last resort.