Zoom on pictures not working

[prettypaperprints]

Anyone else having problems with no Zoom feature on their listings... or on some and not others ?

Some items I list the Zoom works on the 1st image only but not the 2nd or 3rd etc.

Other listings the Zoom doesn't work at all.

All my images are the size they should be.

Thanks

[cq_tech]

Yes, 500px is acceptable, but not large enough to use zoom.