By the way, Proof-of-Stake is an exchange killer. Withdrawal becomes extremely slow, because Proof-of-Stake generation selects/creates too many inputs. Proof-of-Stake is not free for CPU resources of the exchange, that's why any smart exchange operator usually disables it.
Well nothing is for free, but PoS rewards for coins you don't even own is damm cheap.
There seem to be some people that keep insane amounts on exchanges and I see no reason why an operater shouldn't get PoS for handling funds. I don't know the balances of btc-e, but I assume they would be worth the effort. They might just got supriced by too many withdrawls.
The only way I can explain it as rational behavior is to suggest that it is BTC-e covering their short position.
It's not rational to assume that everyone else is rational aswell...
Why shouldn't they be able to buy at their onw exchange? If btc-e had higher prices than vircurex PPC would flow into btc-e and they would get new funds to pay out withdrawls ... They already have a licence to print money, so I assume they won't risk that for a stupid gamble.
I belive it is far more likely that someone simply doesn't trust btc-e and so he takes his buisiness elsewere.