Difficulty Changing Default Runlevel

[zrooze]

I have a knoppix hard disk install that I have been using for roughy 2 years.

Recently I wished to change the default run level of my system (it starts in runlevel 2)
so I changed the inittab file to id:5:initdefault:

Upon rebooting the system still starts in run level 2. It is possible to change the run level
manually by issuing the command init 5 at the shell prompt.

Attempting to change the default run value to level 3 also doesn't work.

Any help or pointers to online documentation that I may have missed would be greatly
appreciated. Thank you.