NOTE: This bug still happen on r163
How to reproduce it:
1. create a new project (or open an existing one)
2. add a sprite
3. paste an image on the image editor (any kind, any size)
4. click outside the image area to remove the selection
5. click multiple times crop transparent edges (double click is enough)
if is not crashed, try again from the point 3, but usually happen at the first time especially if you do all that fast. The faster you do that, higher are the chances of crash.
I'm using Win 7 and I'm copying the image from adobe fireworks