WordPress/Feedburner RSS Errors

I just realized that all of a sudden, for no reason it seems, the WordPress RSS feed on my site has stopped working. If I try to validate the feed, I get the error: “server returned timed out” [here]

I am using the Feedburner Feedsmith Plugin, and the Feedburner RSS Feed is working, but it’s stopped pulling in new posts, and it won’t show the last most recent 6-8 posts or so. I posted a couple new posts earlier today and they never showed up in the RSS feed. I tried using the “ping site” through Feedburner, and that didn’t work either.

It’s really important to obviously get this RSS issue figured out – has anyone ran into any of these types of problems? I moved over to the new feedburner.google.com a few weeks ago but the other sites I moved over are working fine.