I've just started experiencing uploading problems similar to the problems many of us were experiencing back in mid-November.
In October you rolled out the new posting method, and for a month they worked perfectly, but then in mid-November we started experiencing a problem where some images were erroring out on every upload. They will upload on the second try.
That's happening again. It just started, I had a couple images error out yesterday, and through five 24-image posts today 2 or three images errored out on each post. They all went up successfully on the second (in one case third) try.
Please do what you did around November 19 to fix the problem. The system was working absolutely perfectly (and much appreciated!) up until yesterday.
Thanks!