Something tripped the master breaker switch -- we didn't have power anywhere in the house (except for one light in the bathroom -- if that isn't connected to the master breaker switch, that's actually a pretty scary thought). I flipped the switch and the switch of the fuse of the first group flipped off, but power was retained in the rest of the house.
Pretty much everything is on the first group: the kitchen, the TV, the computers...
We disconnected a few wallplugs and flipped the switch of the first group. No problem, power was retained. We reconnected the wallplugs -- no problem.
We now have power everywhere -- but we don't know what caused the problem. All power-hungry devices were off for the night, so my first thought was a computer power dupply that blew up or something -- but that wasn't the case either.
We need to keep an eye on this. And we're late for work. ;)