CUSTOM TITLE/GAME OVER SCREENS

Earlier on, I downloaded a couple of images and tried messing around with them in Photoshop so that I could make myself a title screen and a game over screen for my current project. Later on, I tried them out in RPG Maker 2003, only for the customized pictures to not work. Of course, I tried out the original pictures that the customized pictures were based off of and they worked perfectly. My question is, when it comes to making personal title/game over screens, is there a specific program I have to use or is it that I'm using the correct program, but I apparently did something wrong?