Silverlight Problem with an extra grid cell

[Phil Kestenbaum]

I was able to get a basic grid going: http://img14.imageshack.us/img14/7344/sample2vm.png

as you can see there is an extra cell in the grid with the product categories. I have not been successful to remove this, perhaps someone here can see something,

the code is here:
http://pastebin.com/EWL88e6p