I found what was going on will add it here in case anyone has the same issue:
A few months ago my host was hacked - along with all my sites. Lots of malware links along with theme and WP core hacks. Cleaned all that up and setup stronger security.
Thought I had gotten all the bits from the hack, but there remained one post where a script was placed that hijacked my FB feed. This script redirected my FB feed (though not my WP feed) to a different URL.
I found this by poking around the XML code behind my FB feed. That's when I discovered an old (and pretty popular post) had this redirect script in it. Deleted the script from the post, it stopped redirecting FeedBurner and the redirect code no longer appears in my XML.
That's it. Hope is helps someone.