According to Canon customer service, one should follow the following steps to re-set your camera. It did work for me and the camera works OK
Power Reset
1. Make sure the camera is off, and then remove the battery and memory card.
2. Close the battery door.
3. Press and hold down the on/off button for 1 minute.
4. Release the on/off button, and reinsert the battery and memory card.
5. Power the camera on.
Settings Reset
1. While the camera is on, press the menu button.
2. At the top of the menu move over to the tools tab (wrench and hammer).
3. Go all the way to the bottom of the tools menu list to "Reset All".
4. With "Reset All" highlighted press the Func./Set button.
5. To complete the reset highlight "OK" and press the Func./Set button again.