I just moved servers.
wp_get_attachment_image() or any of its sister functions the image returned is always the full-size image, scaled down, instead of the requested thumbnail size. This has a pretty nasty impact on load times.
Both AJAX thumbnail rebuild and Regenerate Thumbnails those have happily created plenty of thumbnails. WordPress just chooses to ignore them.
Thanks for any help. This might be a dupe of https://wordpress.stackexchange.com/questions/38987/major-issue-with-image-sizes-being-lost-only-full-size-images-being-shown but I'm not sure.
After some research, it appears that the attachment_meta => sizes array on each image has all the correct keys for sizes, but none of the values:
( [width] => 677 [height] => 472 [hwstring_small] => height='89' width='128' [file] => my_original_image.jpg [sizes] => Array ( [thumbnail] => [medium] => [large] => [admin-list-thumb] => [select-a-post] => [detail] => )
Why might this be happening?