There have been discussions on bugtraq about being able to crash some bind-9.1.0 installations with nmap. This is (at least partially) due to some assertion failures. This has been fixed in bind-9.1.1rc1, among other nasty bugs. .. Starting to run out of time though ..
That's part of why I've pushed 9.1.1rc1 into the 7.1 tree about 13 hours ago. ;)