Hello, I wrote the SatoshiRoller software for SatoshiDice. Sorry to hear you encountered this problem. One other case was also reported to me. I have a pending fix that can restore the wallet from this condition.

My working theory is that the block chain file and wallet file have become out of sync. I have not yet determined the precise cause. SatoshiRoller uses the bitcoinj library, and I will be communicating with them about this exception. Thank you for the stack trace.

Until the SatoshiRoller client can be updated, I can help fix your wallet, and you can help me test my repair logic. Please PM me if interested. Sorry for the inconvenience, and thank you for helping beta test.