Ocasionally slow Upload (and download)

[AINSPEED]

I finally decided to change to Utorrent after long years using BitComet. The thing is, a strange thing is happening as I try to use it.

Ihad set up everything, upload and download rates and everything started to work fine, but occasionally, both download and upload rates decrease immensely, the download rate sticks to 10 kB/s to 10.5kB/s max....the upload rate sticks to 0.1 kB/s to 0.5 kB/s maximum.

Also, sometimes only the upload rate decreases and go down to 1kB/s, then for a period of time it never go through that, until it goes back to normal, or the case above.

It happens from time to time. Is it some kind of configuration problem or maybe it's my router or Win Vista? I was using BitComet and never experienced a problem like this, that's why I think it's some config of Utorrent.

I'm using Vista and a router from Thomson named Speedtouch ST510 V6.

Thanks.