Just a suggestion.

When in Real World Cursor Editor, I was creating an arrow with the arrow creator and I accidentally typed in a really big number in arrow head size. My computer tried to load the image (as it was on auto-refresh) however it was really big so it kept on going and the window turned unresponsive. I had to exit it with a task manager. Maybe you should make it so once you get to a certain point (maybe 800?) it doesn't load it as you can't tell the difference anyway with things above about 40.