Just a quick fix for something I couldn’t discount cialis without prescription find earlier:
If you’re on shared hosting which has PHP’s safe_mode enabled, you may run into problems with uploading images. Specifically, you can upload images just fine (assuming you’ve configured uploads correctly) but can’t see uploaded files. This is the case on NearlyFreeSpeech.Net (where my sites are hosted), and probably a few other hosts as well.
WordPress MU uses some .htaccess & PHP tomfoolery to obfuscate the real file path (among other things). Because safe_mode checks to see if the UID/GUIDs match on file_exists(), the script that fetches the images will fail and return a 404. Which is to say, the owner/group of the uploaded file is web/web (or whatever your server’s web user is), but since I manually uploaded the WPMU files originally, those are me/me. Since me != web, it failed. WordPress took this to mean the file was absent and returned 404.
On NearlyFreeSpeech, adding wp-content/blogs.php to the ‘web’ group was all it needed.