Help changing Flash Screens

[saundersag]

I have started a mod based in italy during the renaissance. For my background i would like to change it to a paiting of a battle i have. I resized the image to 800x600. Then i converted it into a truvision image and then replaced the file default parchment narrow. However when i start up total war it just exits just before i get to the menu. Can somone tell me why this is happening and how i can fix it to work.