Guys, check your (MtGox, personal etc.) wallets, there should be a record of the sums sent to CryptoXChange. The address you sent to is the deposit address. Without that proof, you're just helping calculate a total loss, but I don't think you have any claim.
I do arbitrage trading, so I regularly transfer coins all over the place. No way I could tell which addresses were for CryptoXChange with any reliability.
I do have detailed e-mail records of all my trades (hundreds, probably thousands) there from my trading bot though (date/time, amount of trade, BTC/USD balance at the time).