This is why I love excel :P
You have to click and hold on the edge of the selection (the dotted line), if you don't hit that one you will loose your selection :P
I got it working and it is an awesome extension! Thanks!
A question though, if you have a blank Excel cell it doesn't import that blank cell; it moves all cells to the right of the blank one to the blank grid column. Shouldn't it allow blank cells to keep each Excel cell in it's corresponding grid column?