First of all I must warn you that I come from a failed upgrading from Ubuntu 11 to 12.04. Because (i guess) I used wdm instead of gdm. Infact wdm automatically closed during the upgrading and, automatically, gdm starts.
However now, I can't play any sound from normal user, I usually don't get an error, but no sound still come. e.g. If I start banshee it normally works but it stay mute. But I can play everything with the sudo command.
I think a starting point to get the reason is to understand why the normal user don't see a soundcard..
me@this:~$ aplay -l
aplay: device_list:240: no soundcards found...
And from root:
me@this:~$ sudo aplay -l
**** List of PLAYBACK Hardware Devices ****
Home directory /home/me not ours.
card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: Conexant Digital [Conexant Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
thanks in advice