I've been wracking my brain but this is probably simple: I've got a site where I've got thumbnails and titles, etc. displaying on the home.php and categories.php and ultimately search.php and archives.php templates: http://www.dusttoashes.com
The thumbs use the_permalink() to link to the single.php template. The single template displays a larger version of the photo and additional text, etc... basically a modified post format.
The problem is I can't make next and back links stay within the category because the posts are all in multiple categories, and only the lowest # category shows up in the post url. In other words, the next/back is always ALL in the top-level category, not in the category the user was in when they were browsing the thumbnails. So a user is browsing "2011 Rites of Passage" and as soon as they click a thumbnail they're transported into 'all-burning-man-photos' and the next/back buttons are navigating 'all-burning-man-photos'.
I've tried Ambrosite Next/Previous Post Link Plus, but it doesn't help. I thought about a custom taxonomy, but that would mean adding redundant info to hundreds of images already in the database... and it wouldn't solve the problem of overlapping categories.
Maybe I need a custom next/back nav system, but it would have to store which category the user came from on the thumbnail pages...
Any genius out there who can come up with a way to do this, I would be thrilled. Thanks in advance.