More information:-

Hdc seems to be ok as I can mount and work with it from Knoppix4.0 CD.

My HD led flickers in KDE. When using xfce4, the led does not flicker.

"killall automount" allows me to mount /mnt/hdc3 and navigate to it using console. But once I start a file manager (eg emelfm, mc), the system hangs.

I cannot seem to find anything related to automount (or is it S35mountall in rcS.d?).

Though of reinstalling but what if apt-get upgrade produces the same result?

Help appreciated.

BTW, I have another similar unit with Knoppix 4.0 but did not apt-get upgrade recently. This unit seems to be ok.