Default text string appearing in SOME Autoblog generated posts

In testing various configurations for feeds in Autoblog, I've come across some behavior I cannot track down. I have 2 feeds that are set up with identical settings (except from different sites .. but both just rss2 feeds). When posts are created from one of the feeds, every post has this line at the bottom (I've edited out the actual links below):

The post <linked post name> appeared first on <linked source site>.

Where/how is this generated .. I create my own link to source with my own text and don't want this apparent default text to show at all. On the other feed, it doesn't show up.

Does this ring a bell with anyone? I haven't been able to track down the text string in the plugin code so wondering is something on the source sites is causing it?