Do you mean Keyspace, the tech we had before ScalienDB?
Anyway, the reason it was unstable was because we were early in the lifecycle, and as I described in the post, we couldn't get traction, so we also couldn't get investment, so it was just the two co-founders working on it. That's not enough, you need more manpower to do extensive testing of a distributed database which has its own storage engine, esp. when all of it is written in C++ for high-performance. Eg. we only had money to buy 3 servers, we used virtualization to test, but a virtualizated env. is _not_ a proper way to test a database.
Somewhat later, the open source repo scaliendb got pulled only to resurface years later. What happened?