if it's fixing something out-of-the-ordinary that only some clients do, shouldn't it be the default, like the other normalization style?
"You may not always want all of your images to be block elements. Apply the "image_fix" class to any image you need to fix." — so isn't the fix backwards? If the problem is that the clients force a space, shouldn't the fix be to make it inline?
regarding
.image_fix {display:block;}