Another thing to consider is booting with the alsa cheatcode (type: alsa) in addition to setting the release time.

Technical-ish and confusing explanation (hopefully even correct):

From what I understand, normally Knoppix uses the OSS sound driver, but it has a problem: if you start up two programs with sound, 1 & 2, only sound program 1 will play sound. If you close program 1, program 2 will have no sound until you close 2 and start it again.
ALSA is better. It doesn't allow 1 & 2 to make sound simultaneously, but will allow program 2 to make noise once program 1 stops saying it's using the sound driver, which means you don't generally need to close either program.

The Arts sound server is used by KDE and KDE applications. It allows anything using arts to play sounds simultaneously (in theory, I've had spotty results) with other arts programs, and acts as a single sound program (like program 1 from the previous example) as far as alsa knows. Setting Arts to free up the sound device after 2 seconds will allow alsa to switch to other sound programs (such as the Mozilla browser, Gaim Instant Messenging program, XMMS, probably the winmodem) and hopefully vice versa, as long as those programs are nice and don't assume they get to hog the sound device.