By that distribution it's fair to say that your two most recent gifts occurred on Walnut 3. Enough time has passed that Walnut 1 updated for the one before today's gift, and slow ass Walnut 2 hasn't gotten the memo yet for any of them besides the original one, which is strange because it's been a long time since gift #2.
Also note that after some time it appears that the system syncs up and corrects the erroneous double Karma. It won't drop you any, but it won't give you any either the next time you get some, and by that I mean you'll see an increase on the server that it was given on, but the others reject it and when everything updates properly the + goes away on that one server.
Every Karma I've been given has been doubled at the time it was given, yet over time I've lost 7 points of the phantom Karma, which is fine since I wasn't supposed to have it anyway, but it adds to some of the confusion and it's kind of a tease... Like the girl at the end of the bar that eye fucks you until you buy her a drink and then she goes back to hanging out with her friends.