I am having the same problem, and my batch update updated 20 sites, all have the same problem.
I have the same problem with the dutch version.
WordPress gives me now the opportunity to install the stable 3.1.1 english version(wordpress detect I have the 3.1.2. alpha version in dutch). When I than update automaticly the dashboard says “succesfully updated” but still shows I have the dutch 3.1.2.alpha version.
How can I handle this?
I downloaded the Dutch 3.1.1 version, and did not end up with 3.1.2-alpha.
For a short time, the Dutch version of 3.1.1 identified itself as 3.1.2-alpha. This is now fixed.
As posted in another thread, we’re going look into this mistake and aim to prevent it in the future, a download that is marked with the version 3.1.2-alpha is stable (even more stable) than 3.1.1. These packages at most have a single extra bug fix in them.
There is no problem running 3.1.2-alpha, but if you wish, you may re-install 3.1.1.
Closing as resolved.