.
On 11/6/11, my Knoppix 6.7.1 LiveUSB seemed to require adding ntpdate to provide
the correct transition from daylight-savings to standard time via internet access to NTP.

The other settings which without ntpdate seemed all right for Eastern US time until
this Sunday were as follows:

My hardware clock is set to local time; in /etc/default/rcS, 'UTC=no' is set; and in
/mnt-system/boot/syslinux/syslinux.conf, kernel option is set to 'tz=America/New_York'.

I've not changed any of these settings, only added ntpdate via Synaptic.

I think I've found that booting up Windows 7 on the same computer after the time change
has occurred has the same effect, without requiring the addition of ntpdate.