wim, and thats the reason for the block. I think they may be afraid of some insider buyer and they do not want that to create a small price action squeeze which would force them to cover.
that or its just a physc game. put up a huge block that makes people think someone actually wants to sell at that price. who knows if someone came along and wanted to buy say 15k shares at that price it may disappear LOL they may be trying to make people think theres a lot of selling pressure.