This is for a Drupal 6 site, but I've seen this problem with Drupal 7 before too.
I migrated my site from a main domain (www.domain.org, let's say), to a development domain, with a subdirectory, (www.devlin.domain2.com/domainupgrade).
That breaks the images located in /sites/default/files, but not the files located in /sites/all/themes/themename
How can I fix this? I've tried changing file permissions (shot in the dark) as well as the base url setting (but I perhaps didn't change it to the correct value?)
How can I get images to show up in this context on the development site?