From the Neo4j blog:
It’s been just a week since the Neo4j 1.4 M05 release, and though we’re pleased with the way the feature set has evolved, during testing we found a potential corruption bug in that specific milestone.
To address that issue, this week we’re releasing our sixth milestone towards the 1.4 GA release. This milestone is likely to be the last of the series for the 1.4 release, and if the community feedback is positive we will transition into our GA release shortly.
Sounds like Neo4j 1.4 is arriving soon!