I searched through the tickets and didn't find any uploader bugs that were similar to mine, but I apologize if this is a duplicate.
I have 2.5.1 installed on a standard shared web hosting package at Network Solutions. I can upload images, but after they have uploaded, I cannot see any thumbnails, and if I insert the image into a post, it generates a broken link.
I have WordPress installed in the root of my website, and the upload folder is standard(wp-content/uploads), but when I FTP into my site, no files have been added in that directory.
The files are being uploaded, but they are in wp-admin/wp-content/uploads. No matter what I do, or how I edit my upload path, the files are uploaded somewhere in my wp-admin directory.
Searching through the WordPress support forums, I have found several other people who are also having this problem with the uploader
I followed all of Otto42's suggestions in a sticky post in the forum, and nothing seems to affect the results I am having.
I have posted in greater detail about this problem on the WordPress forum:
http://wordpress.org/support/topic/180107
If I can provide more details about this bug to anyone, I would be happy to do so.