I have a Canon PowerShot S400.  One day out of the blue I start to get a message on the screen reading “Memory Card Error”.  Camera no longer will take pictures, and some pictures on the card were corrupt.

Turns out the error is a defect, that Canon will fix, even if the warranty is void.  Details on the Canon coporate web site.

For the images that were corrupt, I found a utility to uncorrupt the images.  Klix software worked for me.