I'm testing the website I'm creating on the newest Opera (21.0.1432.67) on Windows 8.1 64bit. Site link: http://test.theatregames.pl/cast.php?lang=en
At the beginning all the images are there but when you scroll down, stay there for a longer time and then go up, most of the images are gone. It doesn't seem to be a problem when you constantly scroll forth and back. No such problem on other browsers. Any hints? Some kind of browser's optimization stuff?

Thanks,
Mateusz