Problem:
Checking for the input name in the POST variable when using an image type, the PHP looking for the name could not find that input object.
Solution:
Internet Explorer as well as some other browsers, pass the x and y of the image you used for submitting your form instead of the input name. To detect these with PHP, you can check for
isset($_POST['image_x']) || isset($_POST['image'])
if either is true, you can continue to process. You may also note that the browser has converted what would have been image.x into image_x. The period character is swapped out.
Now you should be able to have your input be detected in all major browsers.