I think the problem is mtgox's orderbooks are very thin. at this moment, any speculator can go in bitcoinica with 1000btc, shortsell with 1:10 leverage, and cause the price to go to low 4.xx. The orderbooks just need to muscle up and be able to handle dumps of a couple thousand coins.
Um... who do you expect to muscle up the order books if not for speculators?
I agree that there are people fucking with prices, but you can't just lump all speculators in with a couple assholes.
Also, take a chill pill. I lost more than 5 times what you did, and you don't hear me whining. It you weren't aware of the risks, that's your fault. Man up.