The back-up battery (NV-RAM-backup) does'nt have any influence to that problem. If she goes weak, sometimes EFIKA can loose/change it's MAC, so that registration-key won't work any more (Koszer wrote it). That mostly can be solved by power-on EFIKA without battery and mount a new one during EFIKA is running. In some special cases it does'nt switch back - then you need to contact MOS-Team for a new key-file (that happens to my first EFIKA).

PSU: Should check your capacitors of PSU......

@sailor: I'm curious what will happen to serial log at booting your different cards.......