Use background.png file download from treehouse

I have completed the course and built the app using an image i created myself from photoshop however i wanted to see how the animation looked on the app so downloaded the new files. Ive completely deleted the old files form the folder and uploaded the pictures provided by treehouse. Now when i run my app it still uses the old image to start then when you shake the device to show the predication the animation jumps slightly as the animation picture isnt the same as the one ive created? ive tried to re-write that part of the code but still to no avail?? Also when the image is loaded it almost looks like there is a gap on the right margin, a very thin white line?

Can any please tell me what i have done wrong?