I don't know if this will help, but try:
1. Start without Executive. Executive used to crash my system occasionally, so I got rid of it. (maybe you already tried this)
2. Convert the images you want to use to a different format. Maybe the images are corrupt (this happened to me once) or the datatype being used is having problems (this also happened to me).
3. If the image is larger than your WB screen, trim it to match your WB screen size.