I only know and use apt-get, in knoppix since it has multiple repositories listed, ie: stable, testing and unstable; to install a package from the unstable repository you would use:

apt-get -t unstable install *packagename


Note: you would use " -t unstable " for sid, and " -t stable " for woody otherwise the default in apt.conf is used which is testing. My knoppix 3.1 1-20 release has the following line in /etc/apt/apt.conf:

APT:efault-Release "testing";
...
so by default when you use apt-get install it would look in the testing repository.

HTH

rock