The problem
When I was looking at the dmesg of a Conceptronic CH3SNAS (this is similar to a DS-323), I saw the following lines filled the dmesg.
TWSI: mvTwsiStartBitSet ERROR - Start Clear bit TimeOut .
TWSI: mvTwsiStopBitSet ERROR - Stop bit TimeOut .
I’m using fun_plug on the system to be able to do more with it, but this is also the reason the lines appear in dmesg.
A little search provide me with a forum post which explains how to get rid of these messages.
The solution
In /ffp/start/ntpd.sh change the ntpd_flags to include -x.
ntpd_flags="-x -g -f /ffp/etc/ntp.drift"
And restart ntpd.