Strange behaviour

[wargods]

a few days ago my bitcomet dl and ul speed drop dramatically from the usually more-than-50kB/s to less than 20kB/s and it seems that the dl rate is cap at 30kB/s, while the ul speed drop from 40kB/s to like 20kB/s but will still go up to 40kB/s sometimes. So i done a test on a certain torrent with tons of seed and got connected to a lot of seeders, but it dl at only 10kB/s, however when i tried using other client, utorrent to be specify, the dl is more than 30kB/s. Can someone help me to solve this problem, since i like bitcomet more than other client :P .

PS: it is not my ISP problem, and i use various site to check my dl/ul speed and they are fine, im using DSL btw