Sometimes, the URL's in RSS Feeds are bad, with underscores instead of dashes:
The format with underscores is correct. Where are you seeing links with dashes in them?
I had the same problem with RSS Urls, but I can't figure to remember where it was...
We migrated the Adobe blogs over the summer so it is possible that RSS links were broken from the Adobe Labs site for a day or two. I have since checked/fixed those links so I think that this issue can be closed out.