Utorrent fucking with my internet?

Recently when ever I have utorrent running my internet stops working. I'm thinking its either the port I am using or the speed the program is running at. I have it at unlimited for download and upload so could that be it? Or is there something else that prehaps has been associated with utorrent that makes it act this way?

>>2
What precent of my upload speed should I allow for uploading in utorrent? Using Speakeasy's Seattle server (farthest away from me) I got a 502kbps speed. Using Speakeasy's Atlanta server (Pretty close to me) I got a speed of 713kbps.