Seems there is 2 s0 entries into /etc/inittab:
s0:23:respawn:/usr/sbin/mgetty -x0 -s 38400 ttyS0
s0:23:respawn:/usr/sbin/mgetty -x0 -s 38400 ttyS0
Not sure if I added one line before but now I've 2 lines... so seems update to 7.470 add a new line (or 2) without checking that the line does not already exists...
thx