How to reset RSS feed of new site so nodes from old site will no longer be seen

I created a real mess when migrating some content from an existing site to new site. I have two sites- Site A and Site B. Site A uses Feedburner and synicated my content perfectly. I want to leave that alone

I moved a number of nodes from Site A to Site B and used 301 redirects to do that. My new Site B RSS feed continues to list the nodes of Site A as well as new content I am creating on Site A. However, new content that I am creating on Site B does not show up in the feed.

I also took a look into DB of my Site B and sure enough the current data from the Site A site is there. Now when I create new article for the frontpage of Site B, it does not show up in the feed or on the frontpatge

How can I reset the RSS feed in the new Site B which is running on Drupal 6.10? Also should I delete the Aggregator item sin the data base? I am worried that this will affect my Site A feed which is working well.

One more thing. The RSS icon on my new site shows http://www.mysite-B.com/rss.xml, but when I click on it I get http://feeds2.feedburner.com/Site Articles.

Thanks