Says "downloading" but never any activity

[useruseruser]

queued torrents when i first start utorrent change to 'downloading' and list seeds and peers, but no connection ever occurs. I can get torrents that were very recently posted, but I cannot get any older torrents (even only days old) to download. Its strange because the very recent torrents download at a good speed, but I get absolutely nothing from any other torrent, regardless of its purported 'health'.