To investigate why that image is missing from Project-GC I need to know where to find it at geocaching.com. In what log it exists. I found it in your Gallery at geocaching.com, but that doesn't say anything about the geocache it is bound to.
Then I am not sure what you mean with "hidden cache logs", but I would assume that the code currently only look at images that belong to "found"-logs, we should join in notes, dnfs and such as well.
UPDATE: I have added images from logs that are not finds. After that you have 24 + 1443 images at PGC. I dont' remember if geocaching.com includes those 24 or not. But since the combined number at PGC is 1467 they may not be included. Either that or you have removed images that PGC doesn't know about yet. In the other case, you have uploaded images that PGC doesn't know about yet. I would assume the bug is fixed now. Releasing the fix during the week.