Knoppix 6.4.4 and knoppix 6.7 were reported by a few people to be extremely slow to start in virtualbox. The platforms were not well established but at least on my computer where the host is Linux, it can take a long time, long enough to make one think it is blocking forever. Which it did not, eventually everything seems to work out fine after a long waiting.
After a lot of debugging, I have come to conclusion that the system is blocking at "udevd --daemon". The best part is if you start up knoppix with cheat code "knoppix debug", the system starts up faster than without the cheatcode.
I can't seem to find out why such thing should happen, at this moment. But suffice to say that, I disabled the "progress" update on the screen, then everything works out fine. It boots up as fast as it can be.
If I change the number of CPUs from one to two in Oracle VirtualBox 4.0.12 on a Windows 7 host with an Intel E8400 Core2Duo CPU then Knoppix 6.7.0 starts as fast as usual. It seems that the update of the progress indicator induces a deadlock.
I think that a new cheat code 'noprogressbar' could be useful on some systems.
Knoppix knows how many CPUs are there when it is running. Therefore another approach is to be more generous with the sleep when the CPU is one ( at the expense of a little jerky screen update ). When I put a sleep of 5 second, the booting is very fast. A new cheat code adds complexity. Should be avoided unless absolutely necessary.
On the Debian-Knoppix mailinglist Klaus Knopper recommends the use of of the "splash" boot option in order to disable the progress indicatorRe: Problem running 6.7 DVD iso under VirtualBox-4.0-4.0.12_72916_fedora14-1.i686Code:knoppix splash

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