so I guess its safe to say that type="submit" and type="image" buttons work differently?[/worldwise]
That would be a very good assumption, especially since it should be clear to anyone that there would be no point in having two different input types that would behave the same. In order for one to understand input type="image", one needs to come up with an explanation why it is there anyway.
Image submits were included for the server-side image maps. Similar to a client side image map, where clicking in different areas takes you to different places by providing information on the wheretos and area sizes and positions in the area tag, you can use image submit for the same thing. Except that you do it server-side. Image submit sends coordinates in x (for horizontal) and y (for vertical), telling you where in the image you clicked and allowing you to process that on the server (if the user clicked between 0 <x<100 then perform this).
AFAIK image submits send the coordinates along with the submit name over to the next page. If you use get method in the form and you can see what is passed in the URL address bar -- it would usually look like this ?myButton.x=15&myButton.y=20.
I am not sure what that translates into ASP, I know that PHP interprets (because myButton.x would be an illegal way to write a variable) this into myButton_x. In this way you're right, the button name is no longer carried over to the next page as a true or false value -- the name along with coordinates is. I suggest you inspect the whole Request.QueryString or Request.Form in order to see how the image submit was carried over. Using that you will find out how to reference your button value and will be able to use almost similar code.
Hope that answers it.