UPDATE:
We have eliminated MtGox's BTC value from our data used to calculate our BTC/USD conversion rate and have instead tied our value to Blockchain.info. As of this writing, our conversion rate is now 1BTC = $650.
I have to say CoinBet really came through in this regard. I mistakenly transferred BTC when the rate was really bad. CoinBet generously credited me the difference.
Thanks again!