Weird shiro dsl behaviour?

I dunno if its just me or what ,but whenever my utorrent uploads are finished my net becomes very slow .

I cant open sites for a long time whileas when its uploading i can open upto 5 pages in a row from the same site.I am using firefox btw ,even removed the add ons and other plugins but still

Try Safari, Opera or Internet Explorer 8 (only one of these), also close your utorrent. Maybe some add-on is causing this and isn't completely removed. Do you just feel as if its slow, or have checked its speed at some site like speedtest.net, maybe theres some error or a virus which causes heavy CPU usage after upload is finished.