I am having the same issue, would be interested to hear of a fix or plugin update.
To me it only happened once. Either it is related to the update to WP 3.7 or G+ changed the IDs of the posts for some reason. Can’t really think of any other reason, why this should start failing now.
It happened to me a couple of times over a few months, just hoping that it’s not going to happen again as there were a large number of duplicate posts to remove.
The posts are coming up frequently again. I’ve deleted repeated posts today for the third time in a row. There needs to be a fix for that problem, as it’s hundreds of posts popping up again and again. Can’t delete that stuff all day.
I’ve just had to go through and delete approximately FIVE THOUSAND duplicated posts! I have now deactivated the plugin until the issue is full resolved or I find a suitable replacement, whichever is quicker.
This is really shit, but very hard to debug. I just hope Google hasn’t silently changed something in their API like that old posts are getting new IDs…
Could it be that you deleted the content of the “options” table?
Anyway, I will add in a next version a fallback mechanism to prevent previous activities to be imported again.
I certainly haven’t consciously deleted the options table, I hope this issue is resolves soon as that last one was painful to rectify! Thanks in advance!
I’m still unsure why this happens, but I now release version 1.3.0, which keeps track of every single post ID. Now, this problem could only happen again if Google changes the IDs of the posts after they were imported to your blog, but I doubt they do that.
If the double import happened to you, you might want to take a look at the Bulk Delete plugin (http://wordpress.org/plugins/bulk-delete/), which you can use to easily get rid of those posts, e.g. if you always import them to a specific category. This is of course much easier than manually deleting all those posts.
