I have my feed go to feedburner. It was working fine, then broke (details below). I posted on feedburner forums. After someone looked at it on feedburner forums, they suggested it appears to be my actual WP feed that is broken 'http://pumpjunkies.com/feed'. I don't know what happened but I can tell you, I uninstalled all plugins to see if that was it and it wasn't the problem.
What feedburner details say:
This page contains the following errors:
error on line 1 at column 5639: Opening and ending tag mismatch: encoded line 0 and script"
On feedburner help it also says this:
The URL you entered does not appear to be a valid feed. We encountered the following problem: Error on line 1: The element type "content:encoded" must be terminated by the matching end-tag "</content:encoded>"