Image format used by SEV

Hey guys, I was trying to use a new set of pictures I modified from pre-existing picture to represent a new mount I added in my own mod. In particular its a new mount that I'm playing around with. When I go into the ship editing screen I see the small thumbnail picture just fine in the mount window, but when I right click on the mount to bring up the detail description the game crashes. I'm thinking the 128x128 pixel bmp is the problem but as far as I can see they're just regular bmp with 72 dpi and 24 bit depth and yet the program won't except bmp I created. Has anyone tried adding their own graphics to the game? Does anyone know what format the various pictures should be in?