This may have something to do with your output settings. I experience the same thing on my test site, but I notice it only happens on the main page and not my other aggregate pages. I’m pulling in several feeds and they are filtered to separate pages. I think maybe I did something wrong while tinkering with the output formatting that I didn’t do on the other output streams. (I’m trying to get the source feed links to open in a new window, but have not been successful yet.)
I’ll let you know what I find out as I investigate it further.