After Multi-DB installation and server restart, can't connect to DB

I've migrated on multi-DB about 6 weeks ago, and it works great, both on production, on dev and on local VM. We've dropped the original cluttered DB shortly after migrating to multi-DB.

The local VM is restarted every day, and up until now, I had no problem connecting to the blogs with multi-DB installed.

Today however, I made a new VM, and imported the code and DB over it. All my other websites works great and connect to their respective DBs, but my WP-MU install wouldn't connect. It's looking for the original DB which was destroyed instead of trying to connect to the _global DB defined in the plugin.

Is there a way to make it work again ? Do I need to re-define something ?

This VM config is supposed to be shared and used with our contractors so we need a reliable way to reconnect the WPMU install with its new shiny multi-DB install.

Thanks