Getting sound working for Multiple user log-ins

I have a Suse 9.2 machine which is being used to run desktop applications on KDE for several users, making use of the 'Switch User' feature to keep 2 or 3 users logged in at the same time. Unfortunately, sound only works for the first user logged in, when the second user switches to their desktop KMix is unable to display a mixer for that user. I want the second user to be given control of the sound systems when they log in or switch to there desktop. Can multiple users have access to sound in this way, and, if so, what needs to be in place for this to happen? Ta. -- Colin Murphy - Colin@SpudULike.me.uk