The source version for MySQL Cluster 6.3.31b has now been made available at ftp://ftp.mysql.com/pub/mysql/download/cluster_telco/mysql-5.1.41-ndb-6.3.31b/
This replaces MySQL Cluster 6.3.30 and 6.3.31.
You can either wait for the binaries to be released or if you’re in a rush then you can find instructions on building the binaries for yourself in the earlier article: “MySQL Cluster 7.0.7 source released“.
A description of all of the changes (fixes) that have gone into MySQL Cluster 6.3.31b (compared to 6.3.30) can be found in the MySQL Cluster 6.3.31b Change Log