What kind of server did you upload it on? How did you install WordPress? Are there any other issues?
Watch this post for a reply: http://wordpress.org/support/topic/280366?replies=4
I just asked the guy if he was able to resolve this issue…sounds like the same problem you’re having.
I am using yahoo web hosting services , linux server,
I installed WP through uploading the content with a ftp client. as mentioned in the installation section .
I guess it’s the same problem. stuck with this…
I just changed the upload location under settings > miscelaneous to yearly and all my uploads/pics appear again and it all works again.
I dunno why, but you could try and maybe it fixes your problem too