It certainly wasn't good news for Mayer Brown when partner Joseph Collins was convicted in July of conspiracy, securities fraud, and wire fraud arising from his work as an outside lawyer for the fraudulent brokerage firm Refco Inc. But, as far as the firm is concerned, things could be worse. So far, Mayer Brown has succeeded in beating back nearly every attempt to hold it liable in civil suits for the damage caused by Refco's collapse in 2005. In the latest victory, a federal judge this week dismissed a suit brought on behalf of some of Refco's former brokerage customers who claimed to have lost more than a half billion dollars.