My camera is stuck on the stitch assist mode when I try to put it in auto. How do I get it back to auto?

In the menu try resetting to factory settings.

A stuck shutter is another common failure mode for digital cameras. The symptoms of a stuck or "sticky" shutter are very similar to CCD image sensor failure. The camera may take black pictures (for shutter stuck closed), or the pictures may be very bright and overexposed, sometimes with lines, especially when taken outdoors (for shutter stuck open). To confirm a stuck shutter, put the camera in any mode other than "Auto", and turn the flash OFF (you don't want to blind yourself for the next step). Next look down the lens and take a picture. You should see a tiny flicker in the center of the lens as the shutter opens and closes. If no movement is seen, then you likely have a stuck shutter. If so, please see this link for further info and a simple fix that may help. Recommend the fingertip flicking technique listed in the article/

You're in Stitch Assist (Panorama) mode. Here's your user manual directly from Canon. Page 45 and 46 explains Stitch Assist mode. Page 35 and 36 explains how to select it, and in your case, deselect it.

Go into the camera menu and find "reset"...follow the on-screen instructions.

test

Are you sure that you are in full "auto" mode when you are taking your pictures? Make sure that the mode selector is set to the first red camera (without the M) right next to the little blue arrow.

If you already are in full auto, a stuck shutter is another common failure mode for digital cameras. The symptoms of a stuck or "sticky" shutter are very similar to CCD image sensor failure. The camera may take black pictures (for shutter stuck closed), or the pictures may be very bright and overexposed, especially when taken outdoors (for shutter stuck open).

To confirm a stuck shutter, put the camera in any mode other than "Auto", and turn the flash OFF (you don't want to blind yourself for the next step). Next look down the lens and take a picture. You should see a tiny flicker in the center of the lens as the shutter opens and closes. If no movement is seen, then you likely have a stuck shutter. If so, please see the following for further info and a simple fix that may help:

http://camerarepair.blogspot.com/2009/05/simple-fix-for-stuck-shutter.html

Your camera is not capable of taking 15 second exposures. Instead try putting it in manual mode, turn off the flash, take it in a darkened room, take the picture, and open the battery door while the red and yellow lights are blinking. Give it several tries, but note that the chances may be very slim for success as the shutter symptoms suggest that it is stuck open.

Continuous shooting mode is not available when in Auto, Movie, or Stitch Assist mode. You must select P, Av, Tv, M or one of the preset shooting modes to be able to select continuous shooting. If you didn't get a manual with your camera, you can view / download one here.

If under warranty send it back.
If not replace the camera - these things dont get repaired

stitch assist = panoramic view

since this is just another shooting mode on the camera and that even if you set your camera to another shooting mode, it reverts back to stitch assist, you may need to set the camera's settings back to default. here's a screenshot on how to:

http://i28.tinypic.com/28tkrcg.jpg

from the userguide:

http://www.nycv.com/manuals/Canon/PSS80CUGad-EN.pdf

have you tried removing the batterypack for 10 - 12 hours and again reinsert and check.