Gani Shop crashes when...

[Deeek]

Well, I have a relatively large sprite sheet - about 498 x 1632 in dimension. The editor can load this image fine - the problem is when I use the grid feature to splice the image up into individual sprites (about 249 x 204 in dimension) to make into an animation, the editor crashes. I am, for the record, using Vista. Perhaps I am inputting the parameters in the wrong fields? It states here:
"Specify the rectangle of the image which is drawn"
x:0 , y:0
width: 0 height: 0
So, I input the image's dimensions as the width and height as so :
width: 498 height: 1632
"Instead of a single sprite you can also add an array of sprites, each of the specified width and height. A grid is laid on the image, starting at (x,y). The first sprite in the upper left corner get the sprite indexed typed in above."
grid width: grid height:
So I set x: and y: both to 1, to set them at the very upper left corner of the image, and the grid width and height to 249 x 204, respectively, to splice each individual sprite into a seperate image. As soon as I hit 'Add' the editor apparently becomes overwhelmed and crashes.