After some more testing:
The jpg crashing did NOT happen when I build the game for my Harmattan device, only when trying to build on desktop. I have not tried to build for iPhone or android yet but I guess it will work since that is running on your build server.
Here is an other interesting issue I came across when building on desktop:
As you can see the image to the left is rendered correctly. The left image was created using GIMP. I then saved the same image as JPG, reopened it using GIMP and resaved it as a PNG. This image is on the right and you can see when the image is overlapping the image is not rendered correctly. On my Harmattan phone it is how ever rendered as expected, and hopefully on iPhone and Android too.