Weird. Maybe it's an unforseen side-effect of the recent patch, which was supposed to fix some connection errors in the GTS. I haven't updated to the new version yet, so I'll send something through the GTS and check it out.
Could very well be it. Hell, earlier I had the message saying "Your deposited pokemon has been traded!", saw an incoming JPN Ditto, but had my very same Ditto back in my box afterwards. :/