Comment 10 for bug 465518

solved my issue! Thanks so much!

For info my soundcard and drivers are :

00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
        Subsystem: Giga-byte Technology Device a002
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at e5100000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: [50] Power Management version 2
        Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
        Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
        Capabilities: [100] Virtual Channel <?>
        Capabilities: [130] Root Complex Link <?>
        Kernel driver in use: HDA Intel
        Kernel modules: snd-hda-intel

Codec: Realtek ALC883