it mite just be a frequency change if its just 2 channels, put the box into standby overnite and check in the morning, as that box does a scan in standby mode.
but as said nagra3 is just around the corner and there will be no fix for it so when all channels go then thats it gone, so happy viewing while it lasts.
Do a manual scan as when n3 comes into the stream channels are remapped - you will be ok as long as (a) N1 is still in the stream and (b) they haven't moved these channels to purely the N3 stream (likely)