I've not changed any of these settings, only added ntpdate via Synaptic.
Only installing ntpdate via synaptic is of no use.
You have to run ntpdate either manually or in a cron-job. And it is very important, which parameter you use for ntpdate.

In an earlier posting I mentioned, you will run in trouble with dualboot installation of Linux and Windows, if your BIOS clock isn't UTC.