I have been experiencing difficulties with uploading photos through the Media uploader. All the image files I have tried are relatively small, less than 40kb and less than 400x400px. I have tried all the remedies outlined in the sticky topic above (http://wordpress.org/support/topic/164999?replies=1). I replaced all the WP files, I've deactived/reactived plugins, changed the folder for uploads to be stored and then changed it back to the default, and cleared my temp-files/cache between every attempt (I'm using Firefox, not IE BTW). All with no luck.
When using the flash uploader I get the following error message: Missing a temporary folder.
When using the browser uploader I get the following error message: Error saving media attachment.
I can upload files manually via ftp but that is time consuming and unfeasible for the other authors who will be publishing on the blog.
Could it be an issue with read/write permissions on the server?
Any input or suggestions would be greatly appreciated. Thanks!