Torrents won't download if some torrents are seeding?

Recently, when I download torrent files, they don't download if torrents that were recently downloaded are seeding. If I move the data IN the torrent and remove and delete the torrent itself, other torrents with then start to download. I want to let torrents seed and to keep my ratio up, but I can't seem to figure out how get around things not downloading if things are seeding. What can I do?

I use utorrent.