Error scanning

[EsneyderP]

Hi!
Well, I have a problem to scanning some images. when I edit the size of the image with error, it works, but then, the other qr images get the error.

Both images have the same size, but when I probe them here: http://webqr.com/ I get error with the first image.
Can anyone help me with that? this is happening with a lot of images, and I can't find why. thanks.

Image with error:

Image without error: