According to Housing Wire (apparently via the Huffington Post), approximately 400,000 Independent Foreclosure Review settlement checks were mailed to the wrong address.
There's really not a whole lot to say here. Given that many of the early checks bounced due to Rust Consulting's accounting error, it's not a shock that many checks never made it to the right place. I suspected as much when it was reported that $1 billion in IFR checks were uncashed.
If those 400,000 checks were for $300 each, then that would explain where a chunk of that billion dollars went. I'm willing to bet that all of the uncashed checks are ones that never made it to the right address.