I have a plugin that checks for broken links. I have been getting quite a few broken links from one of my feeds I have set up. Some are genuine broken links in that they were mispelled or wrongly typed in original article, but some aren't.
The ones that aren't are having a %20 (think it is that way and not 20% - I fixed all the links and now typing up I am not 100% certain) added to the end. I checked out the website and the links are correct and I looked at their feedburner feed and the links are correct. I don't know enough about feeds to know where this problem comes from.
The one link which I know keeps breaking is to a linkedin profile and ends with a number. And now I can't remember if the others it was added to had numbers at the end of the link now.