Seriously, you made TWO major changes at once (block size and database type) at once... And deployed in production and partially only (because not all people upgraded).
The problem is older than you think. 0.8 is fine (at least with regards to the current problem). 0.7 had a bug in it and consequently is not capable of handling what it's supposed to be able to handle.
incompatibility between versions should be called (at least) an issue imho...