I'm trying to use Wordpress' built-in thumbnailing and image re-sizing in my Wordpress 2.9.2 installation. I'm trying to get various sizes (post listing/results 160x160 & "single.php" 618x150) and for some reason the single.php one works, but only half way. Not sure if I'm doing something wrong here.

I have it working…sorta. I’m totally stuck and there seems to be a lack of documentation on the Codex for this feature so here goes.

The small 160×160 thumbnail for article listings/search views works fine. It crops it, all’s groovy. The issue comes when I go to format the image for the single.php article details view. It crops, but then scales down even further for some reason.

Screenshot:

http://c1319072.cdn.cloudfiles.rackspacecloud.com/4-15-2010%204-56-46%20PM.png

NOTE: every time I re-test this I’m completely deleting the image from the media section and re-uploading the image entirely. I also have the re-create thumbnails plugin so I know it’s not caching.

Here is my code included in "functions.php". This will help in debugging.

add_theme_support( ‘post-thumbnails’ );
set_post_thumbnail_size( 160, 160, true ); // Normal post thumbnails
add_image_size( ’single-post-thumbnail’, 618, 150, true ); // Permalink thumbnail size