Gutsy nis server and sound permissions

We are installing gutsy on all our office machines (mainly elderly Dell workstations - no problems) and we are serving homes and user accounts using nis and nfs; so far so good - any user can log on at any machine etc. Evry required user has been added to the audio group and the gid is 29 on all machines.However the workstations will only play sound if the user logged on has root permissions. Otherwise the sound is disabled. I realise this is a write permissions thing but I have changed permissions for everything in dev which has "audio" as the group to 666 but to no avail. The gdm login screen makes its little sound correctly.Should I change the default dev group to users instead of audio? Any other ideas?When I cludged a user without using nis/nfs and made them a local member of the audio group it worked OK.-- Many thanks,Derek