I was testing an RSS feed for a new site yesterday, and since Reeder for Mac caches the contents of the feed I couldn't test fixes to it from Reeder. So I went to Google Reader (which Reeder syncs to, of course) to check it out.
Google Reader has a little button on the feed to refresh it, so I was able to force a refresh of the feed and see that the fixes implemented worked.
But what happened after that was a little surprising: three feeds that I'd added to Reeder a long time ago and had never updated (or hadn't updated in a long time) showed up in Reeder with the latest items when I launched Reeder this morning.
So if you're having some issues with Reeder synchronizing things properly, or not pulling down feed items, it may help to just take a visit to the Google Reader web interface. Maybe go visit specific feeds you're having issues with, but I didn't even touch these particular feeds. They just started showing up again.
February 25, 2012