Spam trades like this have been going on for a long time. I really don't understand why Gox can't create patter recognition filters or simply limit the total number of transactions from a given IP. It used to be for the same small amount over and over, now it looks like Gox may have stopped excessitve duplicate orders, but they can't stop changing orders like this.
Probably the same reason why 3 orders in a row causes lag. Still, after all these months. They must be hosting on a c64.