Hi - I'm noticing some weird watermarking behaviour on a client's site. They've set up a default watermark, which is supposed to be added to every image on upload. However if you check out this album:http://retrospectivecycles.com/bianchi-corse-52cm/
Some of the thumbnails link to the standard image URL e.g. `/cache/bianchi-corse-52cm/img_7665_820.jpg`, but others link to e.g. `/zp-core/i.php?a=bianchi-corse-52cm&i=img_7667.jpg&s=820&cw=0&ch=0&q=85&wmk=!&check=67d4e6d0a641a3b8a85f85664a11d7a4d9dbf31b` - which don't load in the lightbox.
Is this to do with caching or watermarks in fact?