About a year ago, I decided to add an autorefresh to pages that contain feeds so that content would always stay fresh. I set it to autofresh every 3 minutes. I could have been done this via ajax, but my ajax kung fu wasn’t good enough then (or now). I went with the easiest method, which is a simple meta tag addition to those pages. I got the idea from Drudge Report.
It was fine for about a year until the week of the Panda Update 2.2, when all pages with the autorefresh would give the Googlebot errors and not get indexed.