Forum Moderators: Robert Charlton & goodroi
As mentioned in the blog post, many cases of duplicate content are unintentional and Google will simply filter out the duplicates and choose 1 version to show in search results. We don't contact webmasters in these cases since it's quite common. Many blog platforms and CMSs generate a certain amount of duplicate content and it's generally not something you need to worry about.Google's Webmaster Central Blog [googlewebmastercentral.blogspot.com]
That said, since Google owns the Blogger platform, I do hope we will see them getting this particular act more together over time.
What you can do is 2 things, first off add rel=nofollow into the template for those links that are generated with the 2nd post. This will not prevent them from being indexed but will prevent them from getting any value and prevent them from taking any value from the original post.
The second thing, while in blogger is difficult, I will propose a option that might work, that is using the rel="canonical" tag and since I don't know how to change the info in the head section for each post at blogger I suggesting just adding it to the post itself. More info on that tag is here: [googlewebmastercentral.blogspot.com...]
The rel="canonical" tag will 100% fix the problem you are talking about, plus since this is a Google invent tag and blogger being Google you might see it automatically added in the future, you might want to direcly email blogger support on this item to be added.