Google App Engine, problems with the launcher update

I am building an application on GAE. It was going fine until the development environment launcher prompted me to update it. I was reluctant about doing it but yesterday I installed the last Windows version (1.4.2). It imported all the projects and the data stores 开发者_运维技巧in the former launcher version, but now when every time I restart the launcher it rolls back the datastore to the state it was before the version update. All the new entities disappear and I only see those that were present before the updating.