FYI, I had "Show in RSS feeds", but Feedburner was telling me the size of my feed was over 512K (not including graphics). It wasn't until I turned the option off that Feedburner would resync my RSS feed and allow it to be published.
This is what I had showing in the RSS feed:
<div class="buttons-wrap clearfix">
<span class="margin15 floatleft">{facebook-like}</span>
<span class="margin15 floatleft">{retweet-bt}</span>
<span class="margin15 floatleft">{stumbleupon-1}</span>
<span class="margin15 floatleft">{plusone-medium}</span>
<span class="margin15 floatleft">{sharethis-classic}</span>
</div>
Have gone back to using Sociable for WordPress 3.0 for the RSS feed.