There definitely some problem with your U torrent settings .
torrents speeds also depend on the kind of seeds you are connected to,the number of seeds and the number of leechers .
You may get low speeds under the following scenario.
1.> You are downloading a torrent which has 700 seeds and 1982 leechers .Then still you will get a low speeds because the seeder to leech is less.
2.> You are downloading a torrent which has 700 seeds and 2 leechers.
Here also you may get low dl speeds because the seeders or leechers you are connected have 256 kps connection. this will be a bottle neck for your 2mbps
connection .
3.>
Also if the peice required is already present in the leecher group ,then it is
not requested from the seed .Only new peices are requested from the seeder
group . .That is why many people with high speeds reduce their download
speeds to get a better ratio .
The best way you can test is by downloading a file from torrent leech .Most
of the guys there have 2mbps + connection .so your connection must be
bottle neck for them .
Also you try U torrent optimistaion guide written some time back .