I have a very strange issue...I can upload images to my main site and sub-domain sites. And I can see these in the relevant site's media manager.
However, when I try to upload an image for use as a custom header (on the twenty eleven theme), it looks like the upload works, but the next step fails...ie cropping to size. Looking back at the media library the image has been uploaded.
My only thought is that either .htaccess in the top-level directory or file permissions are stopping me from editing uploaded files. The blogs.dir directory is set with permissions 0755 recursively.
Has anyone seen this before?