USB SOLUTION:
From
http://tech.canterburyschool.org/tech/UbuntuWorkstationsLogins validated by the Windows server won't correctly pickup membership in local groups, making sound, USB devices, etc. inaccessible. To fix that do the following (Thanks to Steve Towson, Marist Brothers International School, Japan):
1. edit /etc/pam.d/gdm to include
auth optional pam_group.so 2. edit /etc/security/group.conf to include
gdm;*;*;Al0000-2400;floppy,audio,cdrom,video,plugdev,scanner Explanation:
No.1 instructs gdm to use the /etc/security/group.conf
No.2 assigns membership of the floppy, audio, cdrom, video, plugdev (usb sticks) and scanner groups to any user who logs in through the gdm.