Ok do this.
1. Make a backup of all your splash screens.
2. Format your picture to a 1:1 ratio and save it as a .tga file.
3. Rename the pictures to match the names of already existing splash screens. (EX: picture1.tga to Splash_atrofrost.tga)
This is because when the game loads it looks for specific files and not just things that start with Splash (forgot to mention that earlier)
4. Move the new files into the splash folder and overwrite the old ones.
5. Run the game and your load screens should come up correctly.