I use 2 different computers, both with the exact same version of utorrent, both with the exact same settings, but one of them will only upload seed files while the other I can both download and upload.
There is some other software blocking the downloads on my laptop.
The weird thing is, to get around this I installed bittorrent on my laptop which is able to download. Utorrent and bittorrent look and function 100% the same. The difference is in the coding. I think they have two teams of programmers. The only advantage of utorrent is that it has faster transfer rates. I don't know why.
What I do is use bittorrent to download files, and when the files complete, they are imported automatically into utorrent to seed them. That way I can shut down my uploads from my giant 8TB external drive without interrupting my downloads in progress with bittorrent.