I guess I’m trying to be too clever:
I added my Del.icio.us feed to my Google Reader account. Then selected a feed item and clicked Share.
Within Google Reader this works ok. I can click on the link and the corresponding URL opens.
So far so good. No problems.
But if I display the Google Reader RSS feed on an external website such as my blog, the feed adds my Del.icio.us URL to the article’s URL. Which in turn leads to a bad address.
Probably an unintended use…
(update) This is due to the Atom feed. The workaround is to use Feedburner.