iOS 6 image glitch

Hi,

All pages under the work section of my website (https://paulcremoux.com/en/trabajo/) feature a long png. Often images stop loading before they are complete; other times they load and then sort of crash. (You have to have a look at a couple of the pages because it might seem to work fine at first.) I tried saving as jpg and reuploading but it didnt work.

Any ideas?

Only happening on ios6.