I'm not quite sure what the problem is that you're describing, but from what I could gather, Zorro had put "300000" in the bid amount box when the bid was only at "100003", someone else bid "109000" which erased Zorro's "300000" from the bid amount box and replaced it with "109001" instead, and he didn't notice the change and bid anyways, allowing the other bidder to bid one coin higher than that at the last second, thus winning the auction. Am I correct in assuming that is what happened?
If that is what happened, it should not happen again in the future, as I have just fixed this so it will only auto-increment the new bid amount if the latest bid by someone else is more than the amount that you entered for your next bid.