The gallery page I'm having trouble with is here: http://www.elliottwall.com/contents/paintings/
If I sort a gallery to be
image1 image2 image3 image4
image5 image6 image7 image8
but images 1-5 are new uploads to the gallery, the navigation between the attachment pages of each image doesn't go in a corresponding order. Image5 only has only the right arrow, and the arrow should lead to the page of the painting whose thumbnail appears immediately adjacent right in the gallery. Instead, if you begin with image5, clicking the right arrow takes you to image4, image3…image1, THEN clicking the right arrow on image1's page takes you to image6!
I've also tried adding images of much older paintings that belong at say, positions 30-33 or something, and even though I manually sort the gallery thumbnails the attachment page navigation leads to similar huge time warps… the navigation still thinks these newly uploaded images are supposed to be at the end of the list of gallery items. So it seems that the sorting of gallery images is not tied to an ordering of gallery attachment page navigation, rather that media id or post date is taking over somewhere.
I've read a lot about how WP handles galleries but I don't understand this. How can I make my manual slideshow from the paintings page follow my manual sort?
(also, depending on your browser my navigation arrows may appear broken; just remember that that mystery box on the left is supposed to be the left arrow, etc.)