Would be very grateful if you give me link to the page where my button didn't appeared on some photos in 0.7.3

It's true, I changed algorithm a little, in latest version it checks by "physical" size image takes on the page, instead of checking by actual image resolution as it was in 0.7.2. The reason I changed it is because button sometimes appeared on small previews which were actually just big images with small css size, so people simply couldn't click on this previews to check full sized image.

I think I just add a new option to change this behavior. Looks like both cases have their use.