should probably add some more information here, since time was rather limited when posting this originally.
what saved us is that the Mobility Master was up and running.
So for each MD we did this:
1. write erase all
2. full-setup and use same IP-address and network settings as originally used/entered into mobility master.
3. reboot MD after network was configured and the rest of the configuration were once again pushed from MM
neat :)