My feed hasn't updated for 2 weeks and I'm not sure why. I've tried the following:
1) Disabled Feedsmith and any feed related plugins
2) Disabled W3TC and any caching related plugins
3) Set posts that haven't pushed to feed as "draft" again and republished
I think this has happened in the past but I didn't notice until after the fact (when I got a whole heap of new post emails from feedburner at one time). When that happened I'm not sure what broke the feeds and what got it running again.
Here's my feed address: http://norecipes.com/feed/