I've tracked the issue with Opera 12.02 down to broken images + scripts at the top of the page.
While I can get .fail() / isBroken working with other browsers when using the script at the top, Opera just... ignores them.
It works like if the broken images didn't exist, so, it reports that nothing is broken and everything loaded fine, but when the time to execute the code after loading the images comes nothing happens.
What puzzled me is that the example here worked on Opera: http://desandro.github.com/imagesloaded/#!advanced
It drived me crazy until I tried to move the script to the bottom of the page. I guess it's related to $('img').error() working only if placed after the said image.
jsFiddles for testing Opera vs World
With script at the top of the page: http://jsfiddle.net/dF4bj/1/
With script at the bottom of the page: http://jsfiddle.net/dF4bj/2/
I just tested your links in Opera 12.10 and I get the same flawed behavior in both cases. I've had an issue with Opera not firing any load event for cached images. Perhaps it has something to do with that?
Test are passing for v3 in Opera 12.14. I recommend upgrading to imagesLoaded v3 and seeing if thise resolves the issue. Please follow up if you continue to have prop