Strange spikes in download, and strangely high upload speeds

[CamRaiD]

Hi, I have been using utorrent for a good while. And i have on many occasions (not all) found that sometimes the speed at which it downloads rises sharply then falls sharply over and over. I will very rarely achieve more than 60kilobytes down per second, averaging about 18k/sec.

However my upload speed (correctly set according to utorrent help guide) often achieve much more, usually averaging about 30-50 kilobytes per second....

I have been through several guides on what to do and I am stumped. Is this normal ??

Speedtest.net shows me these results;

1.22mb down

0.28mb up

ping 58ms

Sometimes my upload is more like 0.4 - 0.5 mb

My download is never much more than 1.5mb

My ISP does not throttle.

I have included a picture of my utorrent timeline, you can see the upload in red and the download in green. You can also see the upload cap, which i changed during the course of this 1 hour...

http://img515.imageshack.us/img515/8383/uploadpic.jpg

Anyone know whats going on ?? This can't be normal.... ???

[Switeck]

The picture would be much clearer had you saved it in PNG format. Probably would've been smaller too.

1st link in my signature, slow speed section.

Does your problem seem in any way similar to this one?:

http://forum.utorrent.com/viewtopic.php?id=68694