This happened yesterday and is still messing me up.
I tried uploading to Rapidshare yesterday and my upload speeds were fine, for the first minute.. It's usually at a constant 40-45 or 35-40, but after every minute, it would at least decrease by 1 kb and eventually hit an all time low of 12 kbps. It never went back to 40 or 30 like it used to do before. I also tried sites like Megaupload, YouSendIt, Youtube, and the same thing happened. Now it takes at least a good few hours to upload a 100 MB file, when it usually takes at least 30 minutes.. This problem is really annoying, so please help or suggest something that may help.
I think this happened right after I tried tweaking my computer from these sites:
The Complete Guide To Optimising Windows XP | Connected Internet http://intelligentcanuck.com/xp.txt (Mirror)