When working with this program, it may slow down drastically and appear to crash.
In my experience, if you wait long enough for it to do whatever it's doing, it will begin responding again.
Import Image Workaround
The dialog that allows the user to select a portion of an image to import does not appear to work correctly; regardless of how much of the image you select, it only imports the portion selected when the dialog is first shown.
The obvious workaround to this problem is to use another program such as the Gimp to resize your image prior to importing it.