I know I should post this on the WPMU forum, but no one writes me back and I'm just trying to find a larger audience hoping you have run into this issue as well.

I have built a WPMU site for a client, and I am able to upload media into the Media Library and within a Post or Page perfectly. I thought my job was finished, yet the client can't upload any media at all. I'm located in Kentucky, they are located in New England (if that even matters). I had the client record their process of uploading as I thought they were simply not following my instructions for uploading, yet they are doing everything correctly.

When uploading a file it goes through the process of allowing them to select a file and it says it uploads it, yet when it is finished uploading nothing is in the Media Library or in the Post.

Video of the client trying to upload in Media Manager (http://www.screencast.com/users/CatherineWeber/folders/Jing/media/945d33fa-a752-45fd-9bc1-f76fc5a1814a)

Video of the client trying to upload within a Post (http://www.screencast.com/users/CatherineWeber/folders/Jing/media/b5c60e25-f0b5-40c0-a820-c2fc9eb00906)

Asking the client to disable Flash Uploader didn't work :(

Yet, I can login to the WPMU site, access their blog's backend and can easily upload a ton of files. I am so lost at to what the issue is here. I am running version 2.8.4a, and will try to upgrade to latest release hoping this will fix things.