Issue with White Balance - PowerShot A1000IS

[artjewellry]

Hello Experts,

Recently, I changed the white balance mode of my camera to 'Custom White Balance'. While doing this I followed the steps mentioned in the camera:
- Set WB to Custom White Balance
- Point the camera to white color under the light conditions in which I was to do my photography.
- Finally pressed the 'DISP' button to register this custom balance.

Now, the problem is that I am unable to change back the white balance to any other mode - Auto or any other. All the pictures I am taking are totally white.

To fix my problem, I tried the following but none of it helped:
- Changed the WB mode to Auto, cloudy, flouroscent etc. The mode gets changed, but the effect is still of the custom white balance.
- Changed the camera mode to 'Auto' mode.
- Factory reset my camera.

Please help me. This is driving me crazy and it's been a day with this issue, and I still can't figure out the solution.

If need be, I can upload some of the shots which are now coming, and you can see that the complete picture is white (probably becasue when I set the custom white balance, I had used constant light source in a light box/tent)