As much as I've been a supporter of VeriCoin... a fork to roll back the blockchain is a very tough pill to swallow. Have to say I'm with dadams.
I saw three big rollbacks of transactions at mtgox. A fall from 17.50 to 0.0001, a fall from around 15 to 3 and a spike from around 10 to 1000000. Mtgox altered the trade history - was it a problem for investors at that time to stick with mtgox and bring the price to 1200 a year or two later?