It's not true that there was a story by Katherine Mansfield sent in, or rather that would seem to be a kite flown by one of our commenters in a teasing and jocular vein. I don't think Ms Mansfield has a workable email, under the rules, and seances are at best unreliable.
I think I have read all of KM's marvellous stories, seen and heard them performed, for example at last year's Small Wonder short story festivala marvellous production of stories dramatised from "In A German Pension" with Andrew Sachs, the divine Eleanor Bron etc. I've read "Bliss and Other Stories" so many times that the old paperback copy on my shelf is falling to bits.
Regretfully the entries from Hemingway, Nabokov, Carver, and Italo Calvino had to be disqualified on account of the authors being dead (in spite of representations that Raymond Carver's editor had cut the heart out of his work first time round). Most painfully, for me personally, Frank O'Connor too.
For next year, we will try to clarify the rule about the non-eligibilty of posthumous entries. In any case it appears that the entries in some of these cases did not represent their finest work.