No largest when it equals original

I am using image.module,v 1.197.2.3 2006/08/23 20:00:31 and in settings I created one larger size beside the two defaults:

thumbnail 150x400
preview 250x666
columnwide 595x793

When I upload an image with the exact size of "columnwide", then its link will no show any image, only the links to thumbnail, preview and original will work correctly.

Correct behavior would be to remove the link to "columnwide" size because it is equal to the original size anyhow.