In installed OS with following configurations:
knoppix with
KDE version: 3.4.2
System: Linux
Release: 2.6.11
Machine: i686

To launch kde I needed to login thro' console and then using 'startx' kde launches, doesn't start by default.

Reason: (Please let me know if not the same)

While booting process when daemons services starts, 1stly program checks whether that particular service is already running or not by getting it's pid, if it is then 'xxx already running' message is displayed. Same is the case with kdm and is controlled by /etc/init.d/kdm shell script which 'starts or stops the X display manager'. It firstly checks whether kdm is already running or not by matching it's pid with /var/run/kdm.pid if it matches it just displays the message 'kdm already running' without seeing whether kde has started or not. But if we comment out or remove the entry of pid from /var/run/kdm.pid then problem solves. May be since there is no pid available in /var/run/kdm.pid to match, program has to start kde forcefuly.