My issue i have found is that the trackers pass hundreds of new connections my way every few minutes. I limit my upload to 3-5 clients per torrent. checking the logs I see the trackers passing me tens of thousands of new connection attempts even when those 3-5 are full a day.
i think it is a problem with the logic of torrents that the trackers do not know your limits you've set.
My logs on the DIR655 fill up within the hour usually. I gave up on having it send me the logs as the amount of torrent connection failures in them is astounding and makes them useless.
It's none of the routers business if utorrent is going to accept or reject a packet. This is a design flaw, and it shouldn't be rejecting anything on the behalf of your torrent client.
Anyways, your thousands of connections probably have more to do with DHT or PXE. They are known to cause a LOT of connections. (which, I believe, dont actually obey the connection limits but dont quote me).
And, to the OP -- I've had similar problems with more than one dlink router, and most recently I've found that you don't actually have to disable UPNP on the router (which is going to cause you headaches with other software, like MSN messenger for example), you just have to turn off UPNP use in your torrent client. And/or you may also have to turn down your connections through the torrent client as well.